•893-] 69 [Hyatt. 
The phenomenon of karyokinesis hns not been ascertained to be 
universal and its complexity indicates that there are, or have 
been, simpler forms of this process. In fact it is i)ositive]y known 
that fission may occur by the direct process of division or arai- 
tosis and this has been observed in the retrogressive stages of 
cellular division so that it is at present supposed by some to be 
degenerative and to occur only after the cell has passed through 
its karyokinetic or mitotic stages. 
This shows clearly that one cannot assume with certainty that 
normal reproduction by fission in the simplest Protozoa must be 
considered as taking place by the same complicated processes as 
those observed in the Infusoria. If the cycle exists in Protozoa 
as can be reasonably assumed from the phenomena of metabolism 
and the observed degeneration of the nuclei, then one ought to 
anticipate the discovery of some simple mode of cell multipli- 
cation among tlie more genei-alized forms corresponding more 
or less remotely to the amitotic degenerative mode.^ 
Whatever the fate of this prediction, it is quite certain, so far 
as known, that the continuity of the same elements in the nat- 
ural division of cells makes it comparatively easy to explain the 
transmission of likeness, but when that process becomes compli- 
cated with the effects of the conjugation of two organisms, the 
difficulties increase until finally in the bodies of the Vertebrata 
they culminate in a problem of surpassing difficulty. In these 
the ova and spermatozoa are extremely minute and yet through 
them must have come in endless procession all of the thousand 
of characteristics and tendencies derived from the immediate 
ancestors and also many others descended through a chain of 
unknown length from ancestors of unknown antiquity. Put- 
ting the camel through the eye of the needle does not state the 
physical difficulties adequately. 
Every purely corpuscular theory, meaning thereby the physi- 
cnl transmission of gemmules, bio]>hors, pangenes, or any other 
su|'posed organic bearers of characteristics, must not only ac- 
count for a difficulty as great as that of the camel and tlie 
'After this was written I found Joliann Frenzel's paper, "Die nucleolare kern- 
halbirung" (Arch. f. mikr. anat., v. 39, p. 1-32, 1892), in which he claims that 
the amitotic process is followed by the multiplication of cells in ceriain cases amonj;- 
the Invertebrata and refers to Schultze's Rhizopodenstudien, V. (Arch. f. mikr. 
anat., v. 11, p. SS'i-^OS, 1875) to show that the same process lias been observed in 
Amoeba, 
