370 Miscellaneous. 
are completely isolated in the liquid interposed between the solid 
contents of the cyst and its wall move like the others. 
After the lapse of time indicated, this movement of all the spori- 
genous masses ceases suddenly ; each corpuscle returns to a spherical, 
or nearly spherical, form, and becomes converted into a definitive 
spore by the production of a thick wall on its surface. In its turn, 
the voluminous central mass of granules on which the spores rest 
becomes surrounded also with a proper coat, and converted into a 
vesicle enclosed in the cyst and free at all parts. This pseudocyst, as 
I call it, is in my eyes an agent in a new mode of spore-dissemina- 
tion. By its subsequent growth it presses on the spores compressed 
between the opposite surfaces of the two spheres, causes the rupture 
of the exterior tegument, and consequently the liberation of the 
reproductive bodies. 
Out of thirty genera that I have examined, the existence of an appa- 
ratus of dissemination is only met with in the two genera just cited. 
Genera very nearly allied to Gregarina or Stylorhynchus do not offer 
any trace of the peculiarities which characterize these latter ; as, on 
the other hand, the sporoducts and the pseudocyst cannot be brought 
to a common organic expression, it is difficult to decide what value 
it is necessary to attribute, in the characterization of the Gregarina- 
type, to this newelement. But it appears certain that this new ele- 
ment does not create any homology between the Gregarinide and the 
lower plants. The chemical characters of the walls of the sporo- 
ducts and of the pseudocyst, as well as the mode of their formation, 
do not confirm in the least the external analogy that the sporoducts 
of the Gregarine especially seem to bear at first sight to the emis- 
sory tubes of the spores of some Chytridiex.—Comptes Rendus, 
February 15, 1875, p. 432. 
Researches into the History of the Rhizopods. 
To the Editors of the Annals and Magazine of Natural History. 
GuntLEMEN,—It has been brought to my notice, but only within the 
present month, that towards the close of last year Professor Leidy 
published, in some of the American scientific journals, an account 
of researches he had made into the history of the freshwater Rhi- 
zopods, more especially the Amabe and Difflugie. 
I am delighted to find that observations, nearly all of which 
(even to the supposed discovery by Professor Leidy of the very 
remarkable form for which he has suggested the name Ourameba) 
were embodied by me in a series of papers, accompanied by illustra- 
tive figures, which appeared in the ‘Annals and Magazine of Natural 
History’ in April, May, June, August, November, December 1863, 
and March 1864, should have been so fully confirmed by such a 
distinguished writer. It is to be regretted, however, that Professor 
Leidy should have failed to make any reference whatever to my papers, 
although I feel satisfied the failure has been a purely unintentional 
one on his part. I remain, Gentlemen, 
Your most obedient Servant, 
G. C. Wattico, M.D. 
