226 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



Further, Megnin's ligures would not by themselves induce me to fuse 

 the two forms. 



Besides, after considerable study of Ludwig's description, I am unable 

 to decide how much of it represents his own observations and how much 

 is coi)y of Biitschli'sdescription of ^F. ni Ulleri. It seems to be part original 

 and part coi)y, but how much of each it is impossible to determine. 

 It would seem as thouj?h Ludwig first determined in his own mind the 

 specitic identity of the present foriii (il/. sp. 51) with M. mullcri and then 

 applied to the former {M. sp.^X) Biitschli's descrii^tion of M. mulleri, at 

 the same time incorporating therewith certaiu observations, e. g., the 

 dimensions of the spoi-e which must be his own (made upon M. sp. 51) 

 inasmuch as they are not, to my knowledge, to be found in any i)re\"ious 

 description of 31. mulleri. My reason for this view of the subject is 

 Ludwig's statement that — 



I can only confirm Butscbli's results upon the finer structure of Mtjxobolua. 



Further, his figures bear some indication of being semidiagrammatic 

 generalized composites of several of Biitschli's figures of j\[. millleri. 

 And still further his description (except the few additions) is Biitschli's. 

 This course has rendered it impossible for me to distinguish how much 

 of the composite description represents Ludwig's actual observations 

 on j1/, sp. 51 and how much of it merely pertains to M. mulleri generally, 

 and is regarded as api)lying to M. sp. 51, by virtue of its supposed 

 identity with M. miilleri. Under these circumstances I have credited 

 to 31. sp. 51 only the minimum (viz, the residual after subtracting from 

 the com])Osite, Biitschli's description of 31. onillleri); as, though this 

 residual may be incomplete for 31. sp. 51, it is all that can be positively 

 asserted to belong to that species. 



PfeitTer's figures (pi. 25, figs. 5, G) a])proximate the present form much 

 more closely to ilf. ellipsoidcs than to 31. mulleri. 



Finally, Th^lohan says that the present species — 



Presents a groat resemblance to M. miilleri; perhaps it should, however, be con- 

 sidered as speciiically distinct. 



Cyst. — IVIembrane thin, probably formed by host. Contents clear 

 living i)rotoplasm, in which are imbedded very fine dark granules, very 

 small nuclei corresponding to those of true cells, and spores (Ludwig). 



Composed of an irregularly concentric-fibered layer inclosing a second 

 double-contoured layer, which latter surrounds the cyst cavity filled 

 with spores. The large white, stout-walled, walnut-sized, or smaller 

 nniscle cysts are situated near the skin or ])leura; 30, 40, or more 

 jnyxosporidia occur near together, surrounded by a loose web 

 formed by the host. Each myxosporidium is to be regarded as an 

 individual, and the multicamerate tubes result from the common encap- 

 suling by the host of many such individuals of nearly equal age, which 

 individuals subsequently, he thinks (from sarcosporidian analogy, etc.) 

 fuse, the process recalling the so-called conjugation of the large free- 

 living intestinal Gregarines (Pfeifier), 



