68 MARCUS M. HARTOG. 
ciated, may occur in apocytial plants, as through the clamp 
connections! and anastomoses of the Fungi with septate 
hyphe. . 
4. PLASMODIUM FORMATION, that is the cytoplastic union of 
cells without nuclear fusion. This, of course, brings about 
complete mixture of the cytoplasts, comparable to that of the 
nuclei in karyogamy, and which we have termed plastogamy. 
The nuclei are thus furnished with totally new cytoplasts on 
the resolution of the plasmodium into cells. This is a more 
thorough-going process than the preceding, and occurs in 
agamous plants only. It is generally held that karyogamy 
arose aS an advance on this process. 
5. Karyocamy, or the fusion of two or more nuclei as well 
as of their cytoplasts into a uninucleate cell, the zygote, In 
binary union the cytoplast of one of the gametes may be prac- 
tically nil. 
6. THE FUSION OF APOCYTIAL GAMETOIDS. We distinguish 
this for convenience’ sake, as we know nothing of the cytology 
of this process; but it must ultimately fall under the head of 
plasmodial formation or karyogamy ; possibly the cytological 
details may vary even from species to species. 
B. Tue ADVANTAGES OF KARYOGAMY AS COMPARED WITH 
AGAMY AND APOGAMY. 
If the rejuvenescence due to karyogamy be of the nature I de- 
scribe, that is, the formation of a nucleus new to the cytoplast 
with which it is associated, a change in the constitution of the 
‘‘ firm ”’ and “ staff,’ to speak metaphorically, the consequence 
should follow that, by introducing a suitable nucleus into an 
empty cytoplast, we ought to obtain the same rejuvenescence 
1 These are formed by lateral outgrowths above and below a septum, which 
meet and anastomose to form an open loup round the barrier. 
2 Ward, op. cit., p.58, regards the sexual process as ‘‘ consisting essentially 
in the invigoration of the protoplasm ;” but in the preceding pages he clearly 
shows a belief in replacement theories. But his statement “ that the sexuality 
of the higher fungi has disappeared, because its purpose has been equally well 
or better attained otherwise than by means of sexual organs,” is fully in the 
spirit of the views advocated here, 
