226 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



Further, Megnin's figures 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 copy of Biitschli's description of jlf.w«7/eri It seems tobepart original 

 and part copy, but how much of each it is impossible to determine. 

 It would seem as though Ludwig first determined in his own mind the 

 specific identity of the present form {M. sp. 51) with M. miUIeri and then 

 applied to the former {M. sp. 51) Butschli's description of M. miillcri, at 

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

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

 inasmuch as they are not, to my knowledge, to be found iu any previous 

 description of M. miiUeri. My reason for this view of the subject is 

 Ludwig's statement that — 



I cau only confirm Biitscbli's results upon the finer structure of Mijxobolus. 



Further, his figures bear some indication of being semidiagrammatic 

 generalized composites of several of Biitschli's figures of M. mulleri. 

 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 M. sp. 51 and how much of it merely pertains to M. miilleri generally, 

 and is regarded as applying to M. sp. 51, by virtue of its supposed 

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

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

 the composite, Biitschli's description of M. miilleri)- as, though this 

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

 asserted to belong to that species. 



Pfeifler's figures (pi. 25, figs. 5,6) approximate the present form much 

 more closely to M. elUpsoides than to M. miilleri. 



Finally, Thelohan says that the i)resent species — 



Presents a great resemblance to M. miiUeri; perhaps it should, however, be con- 

 sidered as specificallj^ distinct. 



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

 living protoplasm, in which are imbedded very fine dark granules, very 

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



Comi)osed 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 

 muscle cysts are situated near the skin or pleura; 30, 40, or more 

 myxosporidia 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 froju 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). 



