52 SPERMATOGENESIS AND FECUNDATION OF ZAMIA. 
cuss the matter directly, but his figures, 19, 24, 26, and 28, might be 
- taken as indicating an inclosing membrane. Fujii’s figures (40, figs. © 
2 and 5) also represent the formation of the spermatozoids inside of a 
mother cell, although here again apparently no special attention was 
given to this point, and the appearances of the figures, as will be 
shown later, are capable of other explanation. Coulter and Chamber- 
lain have recently called attention to this apparent difference between 
the development of Zama and Cycas and Ginkgo (24, p. 44). The 
same authors draw a distinction between the spermatozoids of Zamia 
and Cycas and those of lower plants which the writer thinks can hardly 
be maintained. They say: ‘‘It is these ciliated cells which have been 
called spermatozoids or antherozoids, and such they are physiologic- 
ally. Morphologically, however, they are sperm mother cells which 
do not organize sperms, a fact which seems true of all spermatophytes.” 
The organization of the whole cell into a spermatozoid is considered 
by them to be very different from what occurs in the Pteridophytes. 
‘The contrast with Pteridophytes, in which each mother cell organ- 
izes an internal ciliated sperm and discharges it, is sharp.” It is 
dificult to harmonize this statement with the recent researches of 
Shaw (102) and Belajeff (12) on Marsilia, where it is clearly shown 
that the spermatozoid is the entire mother cell metamorphosed. It is 
too early to generalize, but the writer is inclined to the opinion that 
where spermatozoids are differentiated inside of a mother cell which 
is discarded it will be found that it is the cellulose shell only, if such 
is present, which is thrown away. The plasma membrane (//aut- 
schicht), from which the cellulose wall is apparently secreted, prob- 
ably draws away from the worthless cellulose shell in the spermatozoid 
formation so that the entire cell, morphologically, is utilized. Noth- 
ing is lost in nature as a usual thing. How then could we expect the 
plasma membrane, which is apparently simply a modified form of 
active kinoplasm, to be thrown away? ‘The fact that a double plasma 
membrane delimiting the daughter cells is first formed in cell division, 
each cell having its own membrane, and that if a cellulose wall is 
formed at all it appears later between these membranes, indicates that 
the wall is of secondary importance, which is further supported by 
the fact that in many cell divisions, as in all the prothallial cells of 
Lamia and Ginkgo, no cellulose walls are formed, the cells being 
delimited only by the plasma membranes. The cell wall the writer 
looks upon as a secretion and not an active organ of the cell, the 
discarding of which could not be looked upon as indicating a different 
morphology. In case more than one spermatozoid is formed within a 
cell their formation must be preceded by karyokinesis, which would 
doubtless divide the protoplast into as many distinct cells. 
Strasburger’s recent investigations of swarm-spore formation may 
be cited in support of the writer’s view on this point. He states that 
