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Fredä M. Bachmann 
differentiated hyphae, but in one case (Fig. 7, PI. XXXI), he has figured 
the cells of a part of tliis hypha as short and thick like those of the car- 
pogone. Baur has figured the carpogones arising from undifferentiated 
hyphae. 
I have found that the number of coils of the spiral constituting the 
carpogone varies from two to three and one-half. Sometimes the spiral 
is loosely and unevenly coiled, more often it is coiled quite evenly. Tliis 
is in agreement with what has been described for others pecies of the 
genus. The number of cells in a spiral varies considerably in different 
lichens. I have found 15 to 25 ; Stahl gives 12 to 25 as the number for 
Collema microphyllum, and for C. crispum Baur gives 15 to 20. In 
Physcia pulverulenta, Darbishire finds 30 to 40. The terminal cell of 
the trichogyne of Coüema pulposum is exceedingly long sometimes sixty 
times as long as wide. Such an elongation of tliis cell has not been des- 
cribed for any other liehen. Stahl found the end cell in C. microphyllum 
somewhat elongated. and for C. crispum Baur describes it as 30 to 40 
microns long and 5 to 6 microns wide. According to Stahl, the terminal 
cell in C. microphyllum is often dichotomously branc-hed. In C. pulposum , 
Stahl figures a branching of the carpogone near the base of the trichogyne 
which occurs in case the trichogyne is not fertilized. In C. crispum Baur 
says that the carpogone remains unbranched unless the trichogyne is 
not fertilized, in which case vegetative branches arise from the coils. 
In Lecanora subjusca, Baur (5) was unable to confirm Lindau’s (60) 
observation of branched trichogynes. In Ramalina fraxinea, Lindau 
found the ascogones branched. I have found in the species I have studied 
that the trichogynes are sometimes branched; usually this branching 
occurs in the penultimate cell. It may be that a branch is only formed 
in case the first trichogyne cell does not fuse with a spermatium. I have 
not found botli branches of a trichogyne attached to spermatia, but the 
one which has not reached a spermatium shows no signs of disintegration. 
However, from the rapidity with which the cell walls of the trichogyne 
become gelatinized, it is doubtful if a second spermatium nucleus brought 
in by a later developing trichogyne could ever reach the ascogone. In 
one instance (Fig. 26, PI. XXXII) I have found the trichogyne un- 
equally branched very near its tip. 
A special covering of gelatinous material on the end of the tricho- 
gyne, such as Stahl and Baur have found in other Collemas, is not 
present in C. pulposum. But since the trichogyne is always completely 
within the thallus such a covering is entirely unnecessary. Such a sticky, 
gelatinous substanee on the tips of trichogynes which protrude may not 
