360 C. H. MARTIN. 
“Jl était visible que la conjugaison avait lieu entre un 
individu riche, et un individu pauvre en tinctine.”’ 
In 1902 Hickson and Wadsworth published a detailed 
account of the conjugation of what was at one time regarded 
as a very aberrant Suctorian Dendrocometes paradoxus, 
owing to the peculiar structure of the tentacular arms. They 
showed that the conjugation in this form was quite analogous 
to the process which occurred in the Ciliata. They found 
that there were normally three micronuclei, which undergo 
two successive divisions. Of the products of these divisions 
one divided again to form the male and female pronuclei. 
After cross-fertilisation the cleavage nucleus divides again 
twice in succession; there appears to be some doubt as to 
some of the later stages in the formation of the new nuclei, 
but normally two micronuclei degenerate; one becomes the 
new micronucleus, and the other develops into the macro- 
nucleus. In other cases the new macronucleus is formed by 
the fusion of two micronuclei, and in still other cases the 
three micronuclei divide again, the later stages in this form 
of evolution of the new nuclei not being followed. There 
are, however, some points in their paper, more especially as 
regards the part played by the macronucleus during this 
process, and also their general conclusions on the morphology 
of the cell body in Infusoria, to which it will be necessary to 
return after describing the conjugation of Acineta papilli- 
fera. 
Methods. — As fixatives, Flemming’s weak solution, 
Schaudinn’s mixture, and corrosive-acetic were chiefly used, 
of which the weak Flemming solution seemed most suitable. 
The preparations were stained either in alum-carmine or 
iron hematoxylin. 
The material fixed in the osmic mixture was treated with 
picro-carmine before staining in alum-carmine. 
ACINETA PAPILLIFERA (Keppen).—This species was first 
described by Keppen in his paper in the ‘Memoires de la 
Societé des Naturalistes de la Nouvelle Russie Odesse’ 
