Marie's prediction proved a true one, for within another fortnight the mulberry buds were tipped with green, and it was evident they would be in leaf with the coming of a few more days of warm sunshine.

"Our silk-growing will begin in earnest now," declared Madame Bretton, "and before it does I think we'd better take one last careful survey of the silk-house to make sure that everything is all right."

From a peg over the fireplace she took down a key, and going out, crossed the lawn to a building which stood opposite. The children danced after her, entering the silent structure with prancing steps. Once inside, however, they stopped their skipping as if automatically and instead began creeping softly about on their tiptoes. Then Pierre glanced up and laughed.

"I declare if we are not as quiet as though the silkworms were here already," said he.

His mother smiled.

"It is force of habit," she answered. "We always have to be so quiet when they are here that it is hard to remember there is no need for the precaution when the building is empty. How odd it is that their hearing should be so acute! No one who has not had the care of silkworms can realize the disastrous results of startling them."

"Father once told me he had known of a lot of silkworms that stopped eating and died because a sudden noise frightened them," observed Pierre.

"Such a calamity is not at all unusual, Pierre," returned his mother. "And more than that, if anything alarms them after they have begun to spin they will frequently snap the thread of their cocoon and refuse to spin any more; if they do continue the interruption causes a lump, or rough place, in the filament so that it is imperfect and has to be broken and tied. In consequence the silk is poorer and brings a lower price. So you see how really important it is not to jar their sensitive nerves."

"Who would think that one of those green caterpillars had any nerves!" ventured Marie. "Is it true, Mother, that a thunder-storm will check their spinning?"

"Yes. It often does if the thunder is very heavy. Your father once lost an entire crop of silkworms because of a severe thunder-storm. The little creatures died of fright. It is wonderful how delicately attuned they are."

"And their sense of smell is so keen," Marie continued thoughtfully. "I remember one day Father hurried me out of the silk-house because I had some perfume on my handkerchief. I was so cross," she added with a shamefaced little flush, "for I thought the perfume very nice and I couldn't understand why he did not like it."

"Miss Vanity!" cried Pierre. "I guess afterward you saw he was dead right. He couldn't take the chance of losing his silkworms, and I don't blame him, either. It is far too much work to raise them; isn't it, Mother?"

"I rather think you will say so when you have raised your own crop," was the quiet answer.

"Do you remember the Italian Father hired to help him once; and how he afterward sent the man away because he would smoke, and smelled of tobacco all the time?"

"Yes. That was another example of the same thing," replied Madame Bretton. "Your father was afraid to risk keeping the man. The caterpillars might scent the tobacco and object to it."

"I had no idea they were so fussy!" gasped Marie. "I do hope our silkworms won't get frightened and die, or else have something make them stop spinning."

"I don't believe they will if we take good care of them," was her mother's soothing answer. "Still, we never can tell. We must heed everything Father has told us if we want to make a success of our task. To begin with there are the mulberry trees—we must not strip them of leaves too early in the season, for if we do the sap will be lost, and the strength of the tree weakened; in addition we must be careful not to waste the leaves by gathering too many at a time, or by getting the wrong kind. You know the worms will eat only freshly gathered leaves. Let us not forget that. And the young silkworms must have small and tender ones. As they grow older they will need more solid food and their development will keep pace with the advancing vegetation. It is the saccharine they take from the leaf that makes them grow; if you feed them tough leaves with little saccharine in them the poor worm has all the labor of eating a vast quantity of material that simply takes its strength and leaves it exhausted and unnourished. Of course we have plenty of leaves to choose from and we shall not need to economize our supply of food. But where people grow silk in great quantities they calculate very closely, and plan to get the greatest number of pounds of silk from the smallest possible number of leaves. That is the way all professional silk-growers work. Paying their leaf-gatherers is quite an expense, and they do not wish this item needlessly large. They buy the leaves by weight, and the leaf purchasers soon become expert in selecting those lots that are the most nutritious; for every one wants his silkworms to grow large and strong so that they may spin fine cocoons and give out a valuable quality of silk."

"Why, Mother, just feeding them is an absolute science in itself then," sighed Pierre in dismay. "I thought if we kept them from going hungry it was all we had to do. We never shall be wise enough to work out such a problem as you have put to us."

"It is not to be expected that we shall," replied his mother kindly. "Such scientific treatment of silkworms takes both knowledge and experience. Many people raise a good crop of cocoons without knowing much more than we do—sometimes not as much. I was only telling you the possibilities of the industry if one were to pursue it on a large scale. If you and Marie and I keep our silkworms alive, clean, and well-fed, and reap a reasonable harvest of cocoons, we must be satisfied. I shall consider we have done well. Only let us not waste more leaves than we must. In time we shall learn to estimate about how many to gather at a picking. Fortunately here in France the mulberry trees yield more leaves than they do in most countries, so I am not worried lest we fall short. In some countries the number of leaves is very limited, and the gatherers are compelled to be exceedingly careful not to waste them. I remember hearing your father say that in Persia, where the climate is very hot, the natives gather small branches of leaves, that they may be fresher than they would be if picked one at a time."

"Why don't we do that here?" inquired Marie. "I should think it would be a fine plan."

"It isn't," responded her mother. "In the first place it injures the trees to take off so many twigs and let so much sap escape; furthermore, it makes more waste to clear away. We should only be making ourselves work were we to follow such a method. The best way is to gather the single leaves just as we always have done. There will be four of us, for old Josef can help us. It is fortunate he did not go to the war, for while he helped your father he learned many things about silk-raising which will be useful to us, I am sure."

"I wish the silkworms did not eat so much," grumbled Marie.

"They must eat if they are to grow, dear," said Madame Bretton. "Every creature eats more while growing—even children," she added mischievously. "But a silkworm does all its growing in a very short space of time, and in proportion to its size grows faster than almost any other living thing. Remember, its whole life is over in a few short weeks. It must live very fast while it lives."

"If only ours do live," interpolated Marie dubiously.

"I see no reason to fear they won't," Madame Bretton said once more. "But we must neglect nothing. It is the trifling carelessnesses that bring bad results—the tiny things that it seems silly to take the trouble to do. If we lose our crop of cocoons because of slighting the little details it will be our own fault, and we shall deserve failure; if, on the other hand, we do the best we know, we shall have no regrets. We must take every precaution to keep the silk-house clean and well-ventilated, for silkworms demand spotless surroundings as well as plenty of fresh air. Then we must not allow withered leaves or other refuse to collect on the shelves where the worms are feeding, for any waste matter ferments and causes disease."

"Aren't silkworms very likely to get sick anyway, Mother?" queried Pierre.

"They are susceptible to certain diseases," nodded Madame Bretton. "For example, there are epidemics which sometimes sweep away the hatching of an entire season; sometimes, too, the eggs are diseased and hatch into diseased caterpillars, which in turn lay more diseased eggs. This was the tragedy that befell France in 1847. At that time the French people could get no healthy eggs anywhere in their own country, and were forced to send to Italy for them. Afterward the infection spread to Italy. Then those from the region of the Danube, where growers had been purchasing them, also became diseased. The plague spread even to China, until in 1865 the only good eggs to be had were those from India. You can imagine what a terrible experience that was for the peasants. Not only did they lose all the eggs that they had raised and stored, but as most of them were poor they could not afford to import perfect eggs from India. Hence many of them gave up silk-raising entirely and the price both of silkworms and of silk became enormous. Only the very rich could afford to buy either."

"How did people ever get out of such a tangle, Mother?" questioned Marie, much interested.

"Little by little those fortunate persons who secured good eggs sold a few to those who had none, and the crop soon increased, for one silkworm-moth will lay as many as two or three hundred eggs. But even at this rate it took many years to get the industry up to where it was before. It was a terrible misfortune to the French and Italian peasants, and you may be pretty sure that as a result of the calamity every one set about being careful to prevent another such disaster. Now when silkworms are ill they are quickly isolated, just as people are who have contagious diseases. And if there is danger of wide-spread infection, and the growers think best not to take any risks, they will even kill many of the caterpillars outright. The sacrifice is sometimes great, but it is a necessary precaution. Furthermore, present day sericulturists have learned much about growing silkworms, and the importance of keeping the silk-houses clean and well aired; they have found that they must preserve an even temperature within the buildings; wash the walls down with lime to purify the atmosphere; sterilize the trays from which the worms feed; and hatch the eggs in large, airy places. The most up-to-date growers who work on a large scale use incubators. Of course, however, there are still some ignorant peasants who insist on hatching the caterpillars inside their clothing, where the warmth from their bodies will bring the eggs quickly to maturity. Fortunately there are not many who do this. They have learned better."

"I should hope so!" ejaculated both Marie and Pierre in a breath.

There was a moment of silence; then the boy looked up into his mother's face and said:

"I understand now why Father was so particular."

"Your father is an intelligent man, who believes that 'trifles make perfection and that perfection is no trifle,'" answered Madame Bretton. "He has raised some very fine silk and made a good profit by selling it. But every franc of the money was earned—it never came to him easily."

"We'll try to do as well as he has, won't we, Mother?" Marie said softly.

"We must not expect to do anything as well as your father would have done it; he has been a very successful silk-grower. But we will do as well as we are able," returned Madame Bretton with a sad, far-away glance.