1904] DAVIS—SEXUAL ORGANS IN PLANTS 245 
The male organs of some other algae, as Oedogonium, are groups 
of closely related cells which constitute a simple tissue, and similar 
conditions are also found in the Rhodophyceae, but all of these 
structures are really clusters of spermatocysts, and can scarcely be 
considered differentiated organs of the plants, even though they 
sometimes have very definite form. Nevertheless, the structures 
frequently are so constant as to have taxonomic value, and conse- 
quently probably always will be called antheridia in the works which 
deal with such matters. 
The sexual organs of Dictyota present conditions that make their 
classification difficult. The cells producing male elements become 
divided (see figures of W1tL1aMs ’o4) into a very large number of 
compartments, each of which develops a solitary sperm. This struc- 
lure seems to be the same as that of the so-called plurilocular sporangia 
of the Phaeophyceae, in which case the male organs cannot be called 
‘porocysts, but are true spermatangia (antheridia). The eggs, how- 
ever, are formed singly in the mother-cells, which are therefore 
eocysts. The significance of these mixed characters in the group is 
not clear. Either the spermatangia (antheridia) are derived from 
spermatocysts that have adopted the peculiar methods of extensive 
cell division characterizing plurilocular sporangia, or the oocysts 
stand as the final stage in a remarkable reduction and final suppres- 
“ion of such activities in an ancestral multicellular female organ 
(oangium), 
The desirability of some system and uniformity in the nomencla- 
‘ure of a group of reproductive organs which are clearly homologous 
_ are the sporocyst, gametocyst, spermatocyst, and oocyst) lies of 
pe in the greater clearness and simplicity of the conception and 
*pression of these relationships. The adoption of a new termi 
*ology for these structures will depend upon how strongly botanists 
may feel the need of these changes. Such old names as sporangium, 
i antheridium, oogonium, and ascogonium would be 
they aah 4 Narrower application, but, as we shall presently explain, 
“¢ not be entirely discarded. 
It will be asked what are the particular advantages of the set of 
ious Sia (sporocyst, gametocyst, spermatocyst, and oocyst) 
erms, and why have not the latter been retained and new 
