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Freda M. Bachmaim 
of a shrinkage of the protoplast, thus having much the shape of an hour 
glass. This change in the shape of the trichogyne cells was observed 
by Stahl, wlio thought it connected with a loss of water and hence of 
turgidity. The disintegrating masses of protoplasm liave the same ap- 
pearance as that described for the antheridial cell of the mildews and for 
the conjugation tube in Pyronema. Harper found that the cell sap in 
these cases disappears, allowing the denser portions to forms a liomo- 
geneous mass which has then an affinity for the safranin. Harper also 
observed that as disintegration continues the mass stains less deeply, 
but that the brown walls remain conspicuous. This is true for my material. 
The brown cross walls are still evident when the cell contents are scarcely 
noticeable. 
Stahl found that in Physma as in Collema the limit of trichogyne 
and ascogone is sharplv defined. He figures the thickened crosswalls 
of Physma graduallv decreasing in thickness near the ascogone but not 
perforated. In this respect my observations on C. pulposum are more in 
agreement with Baur's on C. crispum, according to which there is no 
sharp line of demarcation between trichogyne and ascogone, and the 
cross walls of the former not only are less thickened near the ascogone 
but are plainly broadlv perforated. These openings are never closed. 
This is exactly as I find the conditions in my material. 
Changes in the ascogone following fertilization. 
As a result of fertilization, Stahl, Baur, and Darbishire observed 
that the cells of the ascogone increase in size. Stahl and Baur found 
that the number of cells is increased, and Baur noted also that the newly 
formed septa are entire while the original ascogone cells are plainly per- 
forated. I liave found an increase in size in the ascogone cells but do 
not find any newly formed septa. In C. pulposum, the cross walls of 
the ascogone are almost completely resorbed und the entire ascogone 
becomes praetically one cell. Enough of the margin of the cross walls 
is left so that it is always possible to determine the extent of the original 
cells. Baur was unable to follow the nuclear behavior in the ascogone 
cells, because the dense eontent of these cells and the thick tangle of 
vegetative hyphae which has grown up around the ascogone togetlier 
obscure the nucleus. In the further development of the ascogone, the 
number of ascogone cells of C. crispum is considerably increased by 
interealary division. In Physcia pulverulenta, according to Darbishire 
(25), the cells of the ascogone increase in size and beeome connected 
by means of broad plasma bands so that at last a miütinucleate cell is 
