754 Bachmann . — A New Type of Spermogonium and 
seen. Where there are only one or two spermatia in a group, a single 
trichogyne grows in that direction (Fig. 3) ; if a larger number of spermatia 
are present there is a correspondingly larger number of trichogynes con- 
verging towards them (Figs. 2 and 5)* Frequently the trichogynes from 
ascogones originating rather close together grow towards different groups 
of spermatia. 
We have thus a complete submergence of the sexual apparatus in the 
tissues of the thallus and the consequent complete disappearance of the 
protective spermogonium about the groups of spermatia (Fig. 1). The 
trichogynes seek out the spermatia which have lost even their passive 
motility by means of water or insects. 
The end of the trichogyne is oval, and becomes closely appressed to 
and flattened against the wall of the spermatium. In some cases the tip 
of the trichogyne coils closely about half-way around the spermatium, and 
the opening later between the trichogyne and the spermatium is at the tip 
of the trichogyne and about in the centre, and on the side of the spermatium. 
This is similar to the behaviour of the conjugating tube in Pyronema as 
described by Harper ( 17 ). Here, too, the egg-cell has produced a structure 
which grows out to the antheridium and coils partly around it before the 
conjugation pore is formed. Harper says the conjugating tube applies 
itself closely to the surface of the antheridium and becomes curved, and 
sometimes even hook-shaped, to conform to the surface of the antheridium. 
This behaviour is, in many cases, exactly like that of the trichogyne in the 
form of Collema pitlposum here described. In other cases it does not coil 
around the spermatium, but becomes attached at the side or at the end of 
the spermatium (Fig. 5). In one case a trichogyne was found with two 
free spermatia attached to it. The figures of Stahl and Baur show the 
spermatium attached to the trichogyne a short distance from the tip of the 
latter and the opening at the side and near one end of the spermatium. In 
this species there is no coiling of the trichogyne around the spermatium. 
The several cells next the terminal cell of the trichogyne now begin 
to exhibit characteristic changes. Up to this time the cross- walls have 
appeared thin and sharp in outline. As Stahl observed, however, the cross- 
walls now apparently gelatinize and become very much thickened. This 
thickening is greatest in the centre of the septum, so that biconvex lens- 
shaped walls result ; only occasionally are they biconcave (Figs. 3 and 4). 
This process begins in the most distal of these cells and progresses towards 
the ascogone. The walls nearest the ascogone appear as a thick gelatinous 
plate with a broad opening in the centre. My results on these points are 
in agreement with those of Stahl and Baur. In my preparations made 
with the triple stain these swollen gelatinous cross-walls take a deep orange 
colour with even a very short exposure to orange G. This makes these 
cells extremely conspicuous and easy to find in the sections. The changes 
