40 Wisconsin Academy of Sciences, Arts, and Letters. 
nuclei of these eight cells fuse at once and immediately enter 
upon the prophases of the heterotypic division. Synapsis and 
the reduction divisions are normal in every respect. Thirty- 
two spores are formed. The number of chromosomes, sixty to 
sixty-five, persists through both the gametophytic and sporo- 
phytic generations. 
Whether this is the original haploid or diploid number is not 
at once evident. I am inclined to the view that it is the haploid 
number and that in the evolution of Aspidium falcatum, apog- 
amy appeared before the fusion of the spore mother cells in 
the spore sac. The fern may have existed for some time with 
no nuclear or cell fusion or reduction divisions of any sort be¬ 
fore by further and perhaps correlated variation the fusion of 
the spore mother cells appeared. This seems to me the more 
probable view but the possibility exists that the fusion of the 
spore mother cell appeared first and then led to the immediate 
suppression of the normal fertilization. In this case the num¬ 
ber of chromosomes found at present in both the sporophyte and 
gametophyte would be of course the diploid number. 
There can be no doubt than; the chromosome number in both 
gametophyte and sporophyte is the same in this case as shown 
from the counts described. The nuclei of the prothallium and 
of the sporophyte which is produced vegetatively upon it, con¬ 
tain sixty to sixty-five. 
Winkler (99) classifies the cases of apogamy under two 
heads, (1) somatic apogamy and (2) generative apogamy. 
Under somatic apogamy are included all cases of apogamy in 
which the double number of chromosomes runs through both 
gametophyte and sporophyte. Under generative apogamy are 
included the few known instances in which the reduced chromo¬ 
some number persists through the sporophyte. On this basis 
Aspidium falcatum would be classified as a case of generative 
apogamy. 
In discussing generative apogamy Winkler suggests the possi¬ 
bility that a case might be found in which a haploid gameto¬ 
phyte would produce a sporophyte without change of chromo¬ 
some number and that later in the growth a nuclear fusion 
would make good the sporophyte number. In the case of Aspid¬ 
ium the fusion comes at the close of the sporophyte, showing 
