208 On the Life-History of Pleistophora periplanetae, etc. 



in the life-history of Pleistophora periplanetae is afforded by the 

 existence of residuary nuclei and protoplasm, which die off while 

 sporulation is taking place. The meaning and homologies of these 

 nuclei and accompanying protoplasm are obscure. The subject 

 will be more discussed in the full paper. 



Note on a hitherto undescribed parasite (?) of Periplaneta 

 orientalis. 



In the course of this research certain peculiar structures, which 

 occurred in many of the stained preparations of the Malpighian 

 tubules, attracted attention. They resemble the trophozoites and 

 spores of Pleistophora periplanetae but are smaller in size. They 

 stain in a similar manner with the same reagents. The structure 

 of the trophozoites is however more delicate than that of the 

 trophozoites of the Pleistophora; the nuclei are also smaller and 

 more compact. The spores in the fresh state are highly refringent, 

 resembling the spores of the Pleistophora in this respect. They 

 are, however, much smaller, measuring not more than 1/z — 2/j, in 

 length, and about '5/* in breadth, instead of d'5/j, x 3/a, as in 

 Pleistophora periplanetae. In two cases the chylific ventricle was 

 crowded with these bodies. They do not appear to belong to the 

 life-cycle of the Pleistophora, and it seems probable that they are 

 the trophozoites and spores of a new Myxosporidian parasite. They 

 stand however in need of further investigation. 



