176 The Pehrine Corpuscles in the Silkworm. 



lesions wore not local phenomena, but signs of a constitutional 

 malady, dependent upon a profound cause." 



Pasteur has noted that the development of the pebrine cor- 

 puscles proceeds with an unexampled rapidity during these periods 

 of metamorphosis — a circumstance which our knowledge of the 

 laws of pathology would lead us to expect. He disagrees with 

 Quatrefages in the supposition that the integumentary lesions arc 

 locaHzed foci, from which a quasi-gangrenous process extends to 

 the invasion of adjacent tissue; but considers each stigma to be 

 a resultant of corpuscular development, and the changes in the 

 appearance of the maculae not due to molecular death, but to 

 neoplastic hyperplasia. 



In addition to the symptoms noted above, certain other indica- 

 tions of disease are described in the adult moth, as, for example, 

 vesicles, varices, and buUae filled with a sanguinolent fluid, under 

 or near the wings. Some of these were observed to burst, and 

 their contents, escaping and drying, were found to form adherent 

 crusts, black and viscous, of the size of a pea. 



5. Pehrine and syphilis are alike productive of a specific 

 adenopathy. The secretion of the silk- glands of the pupa has 

 solely contributed to the value placed upon the insect by the com- 

 mercial world. In a pathological point of view, these glands 

 possess especial importance from the fact that they are rapidly 

 affected in pebrine. The large pentagonal cells which surround 

 the canal where the silk is secreted in a viscous state, exhibit in a 

 diseased condition numbers of oval corpuscles, crowded together, 

 and sometimes collected in such masses that they lend an appear- 

 ance of hypertrophy to the glandular tissue. Viewed with a low 

 power, they exhibit whitish projections brilliant in colour, of oval 

 form, and very clear definition. They are, without doubt, evidence 

 of the extension of the disease to the visceral organs of the worms : 

 and the total incapacity of the larves to produce cocoons — those of 

 them, at least, which are profoundly affected — is a proof of the 

 destructive agency exerted by the glandular neoplasms. 



In syphilis, not only are those glands affected which are in the 

 chain of the great system of lymphatics, but those which are 

 actively concerned in haematopoesis. There is strong reason to 

 believe that, aside from the development of hepatic gumma ta, 

 usually found in the tertiary stage, one of the earhest symptoms 

 of constitutional syphilis is dependent upon some disturbance of 

 the glycogenic function of the liver. Dr. Charles Murchison 

 has recently concluded,* after reviewing the discoveries of Hoppe 

 Seyler, Bernard, Lehmann, McDonnell, Hirt, of Zittau, Weber, 

 and Kolhker, that " the glycogen secreted in the liver cell com- 

 bines with nitrogen and forms an azotised jjrotoplasm which main- 

 * 'Laucet,' June, 1874. 



