MICROSPORIDIA 345 



Porter for Nosema apis and N. houihi, Stempell for A^. marionis 

 and Thelohania mulleri, Kudo for Nosema bombycis and recently 

 by Poisson for Toxoglugca mcrcieri (1924) and Nosema nepce 

 (1928). 



b) Schuberg (1910) noted in PUstophora longifilis that the un- 

 inucleate sporoblast transformed itself into a spore without division 

 of its nucleus. Similar observations were made by Weissenberg 

 (1913) in Glugea anomala and G. hertwigi, Debaisieux in Thelo- 

 hania varians, Glugea miilleri, G. danilezuskyi (19 19) and PUs- 

 tophora simulii forms (1928). 



In StempelUa magna, the writer noted the sporoblast is un- 

 inucleate and transforms itself into a spore. There seems to be no 

 nuclear division in this process, but numerous granules were 

 noticed in the developing polar capsule. 



c) In case the sporoblast contains two nuclei, the transformation 

 of the sporoblast into a spore appears to go on without nuclear 

 division or fusion. This state has been observed by Paillot (1918) 

 in Perezia mesnili and P. legeri, Weissenberg (1926) in Nosema 

 binucleatiim, Debaisieux (1928) in Octosporea simulii and 

 Schwarz (1929) in Nosema nonagrice. 



13) Problems of the hypertrophy of the infected host cell. Ex- 

 cept a single species, Nosema binucleatum, which was excellently 

 studied by Weissenberg (1926) and which develops in the inter- 

 cellular space of the host larva, all microsporidia are cytozoic 

 parasites. Not infrequently the infected host cell becomes highly 

 enlarged, due without doubt to the stimulation and increase in 

 numbers of the parasite through multiplication. This has been 

 shown abundantly in the case of Nosema bombycis, Thelohania 

 legeri, T. opacita, StempelUa magna, T. tipulce (Weissenberg, 

 1926), etc. 



On the other hand, there are a number of cases in which the 

 host cell becomes enlarged even though there are only a few para- 

 sitic bodies within it. The writer noted this in Nosema anophelis. 

 Debaisieux (1928) observed also a similar state in Octosporea 

 simidii and remarked that in such a case the cause of hyper- 

 trophy is not due to mechanical action of the parasite, but to cer- 

 tain action which produces the abnormal enlargement of the host 

 cell. 



Still further, there are a number of cases in which no noticeable 

 hypertrophy of the host cell occurs, as was reported by Zwolfer 



