{HE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 261 
structure of the spore, viz, “Its theca shows an oblique striation in 
two contrary directions.” Moreover, he unfortunately fails to indicate 
the species of fishes which he examined.! 
Perugia, however, has given a list of the species of fishes he exam- 
ined, which includes 2 species investigated by Leydig. He says: 
While Leydig had observed that certain spores were striated and others not, 
Mingazztni says that the striz are common to all, and is of opinion that there is 
question of but a single species, an opinion which I believe to be correct. 
In deseribing Chloromyxum leydigii, Thélohan? says it has 
Great strive upon the shell, which, in passing round the posterior part of the spore, 
give it a toothed appearance. 
It is thus evident that he includes with the present species C. inciswm. 
As there is nothing, however, anywhere in the literature to show that 
he himself ever stu:lied the spores of C. ircisum, it is very probable that 
this statement is only intended as representing the consensus of opinion, 
that is, Mingazzini’s and Perugia’s views. 
As regards Mingazzini’s, we have (1) no evidence that he ever 
examined the gall bladder of Raja batis, and (2) only the very loose 
statement given above (which practically amounts to nothing), so that 
his opinion that there is but one species is a mere dictum, and even that 
does not necessarily, as far as the record shows, refer distinctly to this 
case. 
Further, although Perugia notes the discrepancy between Leydig’s 
and Mingazzini’s observations and ranges himself with Mingazzini, it 
appears that he did not examine the gall bladder of Raja batis, and the 
general statement that ‘the striz are common to all” seems to me too 
vague to warrant the fusion of 2 such distinct spore-forms as those here 
separated as Chloromyxum leydigtt and C. ineisum. Until distinet and 
detailed comparisons between the spores habitant in the gall bladder 
of Raja batis and those habitant in the gall bladders of the other 
Plagiostomes shall have been made and properly recorded, the specific 
identity of the 2 forms can not be adimitted. 
Myxosporidium.2—Examined in the bile they have the form of true 
plasmodes, consisting of a diversely ramified, yellow globular proto- 
plasm, movements exceedingly slow. A few minutes after being placed 
on the slide they suddenly undergo modification, throwing out an 
external layer of colorless refracting protoplasm, which (especially at 
the extremities of the individual) suddenly protrudes filiform thin 
pseudopodia, which soon become more robust. They also modify their 
'In this connection the fllowing judicious criticism of Perugia’s upon Mingaz- 
zini’s work may be quoted: ‘ He had an opportunity to make interesting observa- 
tions, but he might well have set them forth in greater detail in his paper, especially 
as regards the various phases of formation of the spore, which he affirms he ob- 
served taking place in the vacuoles designated by Leydig as daugiter-cells” [pan- 
sporoblasts]. 
2 Bull. Soc. philomat. Paris, 1892, tv, p. 176. 
© Description, Mingazzini’s. 
