260 
them that there is necessarily conjugation. Certain Gre- 
garine can become encysted without a foregoing conjugation ; 
but when this conjugation does occur, is its object the fecun- 
dation of the two individuals, the one by the other, the Gre- 
garine being sexual forms? or is it not rather an accidental 
phenomenon? What makes me rather inclined to admit 
this last interpretation is, first, that the conjugation is not 
necessary ; secondly, that this apposition of Gregarine is ob- 
served in certain species in quite young Gregarine ; thirdly, 
that this apposition does not always present itself in the same 
way. Sometimes the individuals are attached by their homo- 
logous extremities, sometimes by their opposite extremities ; 
four thly, that one sometimes finds several Gregarine attached, 
one behind the other (Von Siebold, &c.) ; fifthly, that often 
two Gregarinee enclosed in one cyst do not fuse together into 
a single granular mass, but they give rise, each on its own 
account, to a brood of psorosperms. 
I think it is more just to compare the supposed conjuga- 
tion of the Gregarine to the fusion of Ameboid particles 
forming a plasmodium, as De Bary first observed in the 
Myxomycetz, and Haeckelin the Monera (Protomyzxa auran- 
tica). For in these beings this fusion of elements has simply 
for its object the enlargement of the protoplasmic mass, in 
order to arrive more rapidly at the reproduction by Sporo- 
gonia.! In that case, then, the multiplication by division 
would be the only mode of multiplication in the Gregarine, 
and there would be no digenesis. The multiplication by 
division would be the only one possible; but this manifests 
itself at two distinct stages of their evolution :—1st, it follows 
upon the encystment, and results in the production of the 
psorosperms (sporogonia); 2nd, it takes place in the 
generating Cytod, to produce the pseudofilaria (budding). 
Haeckel has characterised his kingdom of Protista by the 
absence of all sexual reproduction. The Gregarine find 
their place in this kingdom, side by side with the true 
Ameebee. 
1 Haeckel, “ Monograph of Monera,” ‘Quart. Journ. of Microscopical 
Science,’ 1869. 
