V-, THE STATE ENTOMOLOGIST. 89 



They die in all t^orts of j)Ositions, and I hi'.vc many cabinet specimens of 

 such, cleverlj' prepared, stuffed and mounted by the hands of dame 

 Nature. 



Another disease, known as pebrine, has proved extremely fatal in 

 Southern Europe. This is the disease referred to on page 80, which for fif- 

 teen years has almost paralyzed silk-culture in France. It is a disease which 

 in its na lire and action, excej^t in being hereditaiy, bears a striking analogy 

 to cholera among men; and its cause and origin have been the subject of 

 almost as much speculation and study. It has been ascribed variously to 

 the vengeance of _ God, to mildew or other parasitic plants upon the leaves 

 eaten ; and more especially to the artificial manner in which the worms 

 have been raised, some authors roundly asserting that it disappears when 

 the worms are reared in the oj)en air, and that it is the result of a consj)iracy 

 among opticians who have purposely j^ersuaded silk-raisers that a tempera- 

 of 70° Fahr. (24° Cent.) is too cold for the- health of the worms; when in 

 realit}' they can stand with impunity a temperature of four or five degrees 

 below freezing point.* 



Theories and remedies innumerable have been j^rojDOsed, and as is 

 so often the case, those who gave the least study te the disease, were the- 

 most prolific of them. 



The worms affected by pebrine grow unequally, become languid, lose 

 aj)petite, and often manifest discolored spots on the skin. They die at all 

 ages, but, as in muscardine, the mortality is greatest in the last stage. The 

 real nature of this malady was for a long time unknown. In 1849 M. 

 Guerin-Meneville first noticed floating corpuscles in the bodies of the dis- 

 eased worms. These corj)uscles were supj)osed by him to be endowed with 

 independent life ; but their motion was afterwards shown by Filij^pi to de- 

 pend on what is known as the Erownian motion; and they are now known 

 either by the name of panhistophyton, first given them by Lebert; or by that 

 of psoi'ospei'mice. They fill the silk canal, invade the intestines and spread 

 throughout the tissues of the animal in all its different states ; and though 

 it was for a long time a mooted question as to whether the}- were the true 

 cause or the mere concomitant — the result — of the disease; the praiseworthy 

 and assiduous researches of Pasteur have demonstrated that pebrine is en- 

 tirely dependent upon the presence and multiplication of these corpuscular 

 organisms. He has so epigrammatieally analyzed the malady that what 

 was occult and uncurable before has now become clear and comprehensible; 

 and is within man's power to stay or even eradicate. 



The disease is both contagious and infectious because the corpuscles 

 Avhich have passed with the excreta or with other secretions of diseased 

 worms are taken into the alimentary canal of healthy ones in devouring the 

 soiled leaves; and because it may be inoculated by wounds inflicted by the 

 claws. It is hereditary on the mother's side because the moth may have 



* See results of rearing out of doors for four years, bj^ M. le Dr. Jeamiel, of Bordeaux— Bi(Z/f/i« 

 Mens, de la Soc. Imp. Zool. d' Acclimatation ime Serie, Tome VI. Juillet, 1869. A Monsieur Siutrie has 

 also reared the worms successfully and free from disease, in the open air, in France; andJno. S. 

 Gallaher, Jr. , of Washington, D. C. , wrote to tlie Rural Seiv Yorker in August, ISTU, that he had f 1 

 the worms successfully in the open air there. 



