472 INFECTIVE DISEASES. 



prophylactic measures have been described in another chapter 



<P 7). 



Panhistophyton ovatum. (Lebert. Nosema homhycis, Micro- 

 coccus ovatus, Corpuscles du ver-ct-soie). — Shining oval cocci, 2 to 3 /u 

 long, 2 /t wide, singly and in pairs, or masses ; or rods, 2-5 /t thick, 

 and twice as long. They multiply by subdivision. They were 

 experimentally proved to be the cause of pibrine, gattine, maladie 

 des corpuscles or Flecksucht ; and were discovered in the organs of 

 diseased silkworms, as well as in the pupse, moths, and eggs. 



Metchnikoff believes that these micro-organisms are not bacteria, 

 but psorosperms. 



Placherie. 



Silkworms are also subject to a very destructive disease known 

 as flaoherie, flaccidezza, maladie de moi-ts blancs. The worms cease 

 feeding, die and become a putrid mass. The disease is dependent 

 upon bad hygienic conditions, and is very infectious. The cause 

 has not been determined with certainty, but it has been attributed 

 to a streptococcus. , 



Streptococcus bombycis {Mikrozyma homhycis, Bechamp). — 

 Oval cocci 1'5 ytt diam., singly, in pairs, and in chains. They are 

 said to be present in dust from infected localities. 



Disease of Caterpillars. 



Forbes has described an infectious disease of the larvse of a 

 caterpillar {Picris rapce). Cocci which were found singly and in 

 masses, were regarded as the cause of the malady. 



