822 TROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



of the spores by Mr. Hutclimson's method is not possible, but acute in 

 the ovaries and egg-cells. Such cases, which should not he allowed to go 

 ^undetected, can be easily noticed by the Pasteur method. As a rule pebrine 

 spores are seen more in the fatty tissues, muscles and membranes of 

 the tracheal branches of silkworms than in the gut, though in Afis 

 mellifera pebrine spores are always confined to the gut and malpighian 

 vessels. " Pasteur himself advised to examine the alimentary canal 

 of the caterpillars and pupse, as it is difficult to detect the pebrine 

 corpuscles when they remain mixed up' with the innumerable fatty 

 globules because the multiplication of the spores is limited at the time, 

 but in the case of moths he has advocated the examination of the entire 

 moth and not the alimentary canal only as pebrine bodies would multiply 

 sufficiently in this stage " {vide Mr. Lambert's letter, quoted ante) 

 If pebrine corpuscles infest only the mid-gut and not the female genera- 

 tive organ they will exercise the same influence over the progeny as 

 the sperm of a pebrinized father-moth, which is generally not examined 

 for elimination of hereditary pebrine. The corpuscles cannot be trans- 

 ferred in the egg-cell if only the mid-gut is affected with them ; they can 

 only be transferred in the egg-cell if the female generative organ is affected , 

 and hence that organ must be examined for elimination of hereditary 

 pebrine. The above savants did not think it safe to examine the gut only 

 or any particular part for elimination of hereditary pebrine. 



Mr. Honda, in his letter to me of the 17th May 1918, writes " Whe- 

 ther or not there is any other way to infect than the alimentary canal is a 

 question which we cannot yet decide. However, I don't hesitate to assert 

 that the normal way is the alimentary canal." 



3. Infection through ivounds in fJie Chitin. 



Silkworms may be attacked with pebrine (though rarely) through 

 wounds in the chitin and then to the various internal organs. 



M. Pasteur observed pebrine bodies through wounds in the skin 

 by infecting pebrine corpuscles with a needle. He says in his Etudes 

 sur la maladie des vers a 50/e, page 130, published in 1870, " Dans le lot 

 temoin, pas un seul des papillonsn'a offert la moindre trace de corpuscles, 

 Dans le lot contagione par la nourriture, tons les paj)illons, sans excep- 

 tion, furent corpusculeause de 100 a 200 corpuscles par champ. 



" Enfin dans le lot contagionne a I'aide de blessures injectees, sept 

 papillons seulement offrirent des corpuscules, de 50 a 200 par champ. 



" Le contagion par piqures inf ectees a done lieu, mais elle est moins 

 sure que par le canal intestinal, ce a quoi il faillait s'attendre, parceque 

 le sang qui de la blessure ne laisse pas touj ours penetrer les corpuscules 

 qu'on cherche a inoculer." 



