ATKINSON: THE GENUS ENDOGONE 9 
but I am strongly inclined to believe that they are spores of some 
parasite. 
RELATIONSHIPS OF ENDOGONE 
The coenocytic mycelium with no true cross walls, except those 
which separate reproductive organs from the mycelium, with the 
formation of resting zygotes soon after the conjugation of gametangia, 
are phycomycete characters. The method of conjugation of equal or 
slightly unequal gametangia indicates a closer relationship with the 
Zygomycetes than with the Oomycetes, although in Endogone lactiflua 
the content of the small gametange, or antherid, flows into the larger 
one which is comparable to the oogone. In Zygorhyncus the two 
gametangia are very unequal in size, but the zygote is formed within 
and includes all of both gametangia, a strictly zygomycete feature. 
In Conidiobolus the gametangia are of very unequal size, and are 
worthy of being distinguished as antherid and oogone. The content 
of the antherid passes into the oogone within which the zygote is 
formed. In Basidiobolus? also there is a supplying gametange and a 
receiving one, but other features of these genera, especially conidial 
formation, show such a close relation to Empusa that they are generally 
regarded as members of the zygomycetes with a leaning toward the 
oomycetous type of fructification, but not having reached the char- 
acteristic feature of egg differentiation in the oogone. Endogone 
departs from the usual type of zygote formation present in the zygo- 
mycetes. The zygote is an outgrowth from the conjugation point of 
the gametangia (E. sphagnophila), or from the larger gametange 
(E. lactiflua, rarely in E. sphagnophila). A similar situation, however, 
is present in Piptocephalis freseniana and in Empusa (Entomophthora) 
fresenit, where the zygote is an outgrowth of the point of conjugation 
much as in Endogone sphagnophila. In Empusa occidentalis, echino- 
spora, sepulchralis, etc., the zygote is an outgrowth of one of the 
gametangia, a situation similar to that in Endogone lactiflua, or some- 
times it arises from the point of conjugation in these species of Empusa. 
In the selection of a single sex nucleus in each gametange, E. 
lactiflua presents a situation similar to that in the Peronosporales, 
though there is no differentiation of ooplasm and periplasm in the 
oogone of Endogone lactiflua, as there is in the Peronosporales. In E. 
sphagnophila there is no sex selection of nuclei in the gametangia so 
far as we can determine, for all of the nuclei without manifesting any 
differentiation pass with the cytoplasm into the new outgrowth where 
the zygote is formed. The nuclear behavior in the zygote has not 
yet been made entirely clear. The present evidence suggests that 
2 Basidiobolus by some is placed in a distinct family. 
