152 MICROBES, FERMENTS, AND MOULDS. 



own researches soon induced him to adopt the 

 same view. 



The pebrine microbe was long regarded as a true 



bacterium, successively described as Bacterium 6om- 



bycis, Nosema bombycis (Fig. 72), and 



0"'^ & Panistophyton ovale. Balbiani's recent 



* 0^0 ^ researches tend to show that it should 



^ Q o be assigned to another group, much 



9 nearer to animals, and designated 



Fig. 72. Nosema SpOTOZOOLria, 



bombycis, pebrine 9 



microbe (x 500 SpoTozoaria. These protista, still 



regarded as plants by many naturalists, 

 chiefly differ from bacteria by their mode of growth 

 and reproduction, in which they resemble the para- 

 sitic protozoaria, termed Psorospermia, Coccidies, and 

 Gregarinidce. 



In Sporozoaria, growth by fission, the rule in all 

 bacteria, has not been observed ; this distinction is 

 fundamental. Sporozoaria multiply by free spore- 

 formation in a mass of sarcode substance (protoplasm), 

 resulting from the encysting of the primitive corpuscles 

 (mother-cells). The formation of numerous spores 

 may be observed within the mother-cells, having the 

 appearance of pseudonavicellce or spores of gregari- 

 nidaeand psorospermia (parasites of vertebrate animals). 

 Balbiani forms these organisms, which are found in 

 many insects, into a small group, which he terms 

 Microsporidia. 



The ripe spores are the vibratile corpuscles of 



