A. Henfrey on the Higher Cryptogamous Plants. 35 
they suffice to warrant the belief in the existence of a distinction 
of sexes in these families. In the second place, we have to e 
deavor to trace the analogies which exist between the different 
ent families. These considerations, if we adopt the hypothesis 
of sexuality, lead to some very interesting questions in reference 
0 the process of reproduction generally. 
In regard to the first question, that of the existence of two sexes 
and the necessity of a process of fertilization, we have several 
kinds of evidence. nt Ey 
he inferences to be deduced from the universality of the 
existence of two kinds of organs in connection with the repro- 
ductive process. We have seen that these exist in all the families 
at some period or other of the life of the representative of the 
species. In the Mosses and the Hepatice they occur in the fully 
developed plant. In the Ferns and Equisetaceze they oecur upon 
cellular structures of frondose character developed from all the 
Spores, which frondose bodies or pro-embryos have an existence. 
of some permanence, especially in the Equisetacee. In the Ly- 
Copodiaceae, the Isoétacee and Rhizocarpez, the pistillidia occur 
Upon very transitory cellular structures produced from one kind 
of spore, the larger; while the smaller spores at once develop in 
their interior cellules containing moving spiral filaments, such as 
occur in the antheridia of the other families 
2. The inferences to be deduced from the observations on the 
development of those plants in which the two kinds of organs, 
eecurring in distinct places, can be separated. Strong evidence 
has been brought forward that the dicecious Mosses, as they are 
ed, do not produce sporangia when the pistillidia are kept apart 
ftom the antheridia by natural accident. ‘The majority of ob- 
Nigeli Hofmeister and Mettenius to have been based on very im- 
Perfect observation. 
|The Circumstantial evidence furnished under the first head 
MS to me very strong, so much so that I am inclined to adopt 
bad idea of sexuality on this ground as the legitimate provisional 
hypothesis arising out of our present kno wledge, especially 
