i20 



THE LANCASTER FARMER- 



[August, 



ditary, bears a striking analogy to cholera 

 among men. "The worms affected hy pebrine 

 grow unequally, become languid, lose appetite 

 and often manifest discolored spots upon the 

 skin. They die at all ages, but, as in muscar- 

 dine, the mortality is greatest in the last age. 

 The real nature of this malady was for a long 

 time unknown. In 1849 M. Guerin-Mene- 

 ville first noticed floating corpuscles in the 

 bodies of the diseased worms. These corpus- 

 cles were supposed by him to be endowed with 

 independent life, but their motion was after- 

 wards shown by Pilppi to depend on what is 

 known as the Brownian motion, and they are 

 now known cither by the name oipanhisioi)hy- 

 ton, first given by Lebret, or by that of pso- 

 rospermim. They fill the silk-eanals, invade 

 the intestines, and spread throughout the tis- 

 sues of the animal in all its different states; 

 and though it was for a long time a mooted 

 question as to whether they were the true 

 cause or the mere result of the disease, the 

 praiseworthy researches of Pasteur have dem- 

 onstrated that pehrinc is enttrely dependent 

 upon the presence and multiplication of these 

 corpuscles. He has analyzed the disease so 

 clearly that not only do we see its nature, but 

 we are able to point out the remedy. The 

 disease is both contagious add infections, be- 

 cause the corpuscles which have been passed 

 with the excrement or with other secretions 

 of diseased worms have been taken into the 

 alimentary canal of healthy ones in devouring 

 the soiled leaves, and because it may be inoc- 

 ulated by wounds inflicted by the claws. It 

 is hereditary on the mother's side, because 

 the moth may have the germ of the disease 

 and yet oviposit. Indeed, the eggs may be 

 affected and yel look fair and good, the micro- 

 scopic psorospermix not being visible, so that 

 the only true test of disease or health is an 

 examination of the parent moth; and by kill- 

 ing off all infected moths the disease can be 

 controlled. 



"Both the diseases mentioned are, there- 

 fore, in the strict sense of the word, silk-worm 

 plagues; the one of a fungus and the other of 

 an epizootic nature. Each may become epi- 

 demic when the conditions are favorable for 

 the undue multiplication of the minute or- 

 ganisms which produce them, or when the 

 checks to the increase of such organisms are 

 removed by carelessness or ignorance. " Clean- 

 liness and purification are absolutely necessary 

 in treating both these diseases, and in pebrine 

 care must be taken that the eggs are sound 

 by a microscopic examination of the moths. 

 This may be done after the eggs are laid, and 

 if the corpuscles be found in the mother, her 

 eggs should be discarded. 



Silkworms are suliject to other diseases, 

 but none of them have acquired the impor- 

 tance of those described. What is called 

 (jattine by older authors is but a mild phase Of 

 pebrine. The worms are apt to be purged by 

 unwholesome leaves; too great heat makes 

 them sickly, or they may become yellow, 

 limp and die of a malady called grasscrie or 

 jaundice, which is almost sure to appear in 

 large broods, and which is very common 

 in those reared in this country. When 

 the worms die from being unable to molt 

 they are called lusettes, and such cases 

 are most abundant at the fourth molt. All 

 these different ailments, and others not men- 



tioned, have received names, some local, 

 others more general; but none of them war- 

 rant further notice here,as they are not likely 

 to become very troublesome if proper atten- 

 tion and care be given to the worms. 



Varieties of Races. 



As before stated, domestication has had 

 the effect of producing numerous varieties of 

 the silkworm, every different climate into 

 which it has been carried having produced 

 either some changes in the quality of the 

 silk, or the shape or color of the cocoons, or 

 else altered the habits of the worm. 



Some varieties produce but one brood in a 

 year, no matter how the eggs are manipulated; 

 such are known as Annuals. Others known 

 as Bivoltins, hatch twice in the course of the 

 year; the first time, as with the Annuals, in 

 April or May, and the second, eight or ten 

 days after the eggs are laid by the first brood. 

 The eggs of the second brood are only kept 

 for the next year's crop, as those of the first 

 brood always either hatch or die soon after be- 

 ing laid. The Tremltins produce three an- 

 nual generations. There are also Quaclrivol- 

 tins, and in Bengal, a variety known as 

 Bacey which is said to produce eight genera- 

 tions in the course of a year. Some varieties 

 molt but three times instead of four, espe- 

 cially in warm countries and with Trevoltins. 

 Experiments, taking into consideration the 

 size of the cocoon, quality of silk, time occu- 

 pied, hardiness, quantity of leaves required, 

 etc., have proved the Annuals to be more 

 profitable than any of the Polyvoltins, al- 

 though Bivoltins are often reared; and Mr. 

 Alfred Brewster, of San Gabriel, Cal. , says 

 that he found a green .Japanese variety of 

 these last more hardy than the Chinese An- 

 nuals. Varieties are also known by the color 

 of the cocoons they produce, as Greens or 

 Whites or Yellows, and also by the country 

 in which they flourish. The white silk is the 

 most valuable in commerce, but the races 

 producitig yellow, cream-colored or fiesh- 

 colored cocoons are generally considered to be 

 the most vigorous. No classification of va- 

 rieties can be attempted, as individuals of the 

 same breed exported to a dozen difl'erent lo- 

 calities, would, in all probability, soon pre- 

 sent a dozen varieties. The three most 

 marked and noted European varieties are the 

 Milanese (Italian) breed, producing fine small 

 yellow cocoons; the Ardeche, (French) pro- 

 ducing large yellow cocoons, and the Brousse 

 (Turkisli)produclng]large white cocoons of the 

 best quality in Europe. Owing to the fearful 

 prevalence of pebrine among the French and 

 Italian races for fifteen or twenty years back, 

 the Japanese Annuals have come into favor. 

 The eggs are bought at Yokohama in Septem- 

 ber, and shipped during the winter. There 

 are two principal varieties in use, the one 

 producing white and the other greenish co- 

 coons, and known respectivelly as the White 

 .Japanese and the Green Japanese Annual. 

 These cocoons are by no means large, but 

 the pods are solid and firm, and yield an 

 abundance of silk. They are about of a size, 

 and both varieties are almost always con- 

 stricted in the middle. Another valuable race 

 is the White Chinese Annua whicli much re 

 sembles the White Japanese, but it is not as 

 generally constricted. 



Wintering and Hatching the Eggs. 



We have already seen the importance of 

 getting healthy eggs, free from hereditary 

 disease, and of good and valuable races. 

 There is little danger of premature hatching 

 until December, but, from that time on, the 

 eggs should be kept in a cool, dry room in tin 

 boxes to prevent the ravages of rats and mice. 

 They are most safely stored in a dry cellar, 

 where the temperature rarely sinks below the 

 freezing point, and they should be occasion- 

 ally looked at to make sure that they are not 

 affected by mold. If, at any time, mold be 

 perceived upon them it should be at once 

 rubbed or brushed off, and the atmosphere 

 made drier. If the tin boxes be perforated 

 on two sides and the perforations covered with 

 fine wire gauze, the chances of injury will 

 be reduced to a minimum. 



The eggs may also, whether on cards or 

 loose, be tied up in small bags and hung to 

 the ceiling of the cold room. The string of 

 the bag should be passed through a bottle 

 neck or a piece of tin to prevent injury from 

 rats and mice. The temperature should never 

 be allowed to rise above 40^ F., but may be 

 allowed to sink below freezing point without 

 injury. Indeed, eggs sent from one country 

 to another are usually packed in ice. They 

 should be kept at a low temperature until the 

 mulberry leaves are well started in the spring, 

 and great care must be taken as the weather 

 grows warmer to prevent hatching before 

 their food is ready for them, since both the 

 mulberry and Osage orange are rather late in 

 leafing out. One great object should be, in 

 fiict, to have them all kept back, as the ten- 

 dency in our climate is to premature hatching. 

 Another object should be to have them hatch 

 uniformly, and this is best attained by keep- 

 ing together those laid at one and the same 

 time, and by wintering them, as already re- 

 commended, in cellars that are cool enough 

 to prevent any embr3'onic development. 



They should, then, as soon as the leaves of 

 their food-plant have commenced to put forth 

 be placed in trays and brought into a well- 

 aired room where the temperature averages 

 about 75° F. If they have been wintered 

 adhering to the cloth on which they were laid, 

 all that is necessary to do is to spread this 

 same cloth over the bottom of the tray. If, 

 on the contrary, they have been wintered in 

 the loose condition, they must be uniformly 

 sifted or spread over sheets of cloth or paper. 

 The temperature should be kept uniform, and 

 a small stove in the hatching-room will prove 

 very valuable in providing this uniformity. 

 The heat of the room may be increased about 

 2-' each day, and if the eggs have been well 

 kept back during the winter, they will begin 

 to hatch under such treatment on the fifth or 

 sixth day. By no means must the eggs be 

 exposed to the sun's rays, which would kill 

 them in a very short time. As the time of 

 hatching approaches the eggs grow lighter in 

 color, and then the atmosphere must be kept 

 moist artificially by sprinkling the floor, or 

 otherwise, in order to enable the worms to 

 eat through the egg-shell more easily. They 

 also appear fresher and more vigorous with 

 due amount of moisture. 



Feeding and Rearing the Worms. 



The room in which the rearing is to be 

 done should be so arranged that it can be 



