394 
Mot tier. — Contributions to the 
traces of the acid are removed, a condition so necessary when 
it is desirable to stain with alum-cochineal. They were then 
stained in toto with alum-cochineal, dehydrated, brought 
gradually into a solution of turpentine and paraffin, imbedded 
in paraffin, and sectioned on a Minot-microtome. The 
sections were counter-stained on the slide with Bismarck- 
brown dissolved in 70 per cent, alcohol, and mounted in 
Canada-balsam. The nucleus and parts of the protoplasm 
are stained by the cochineal, and the cell-walls by the 
Bismarck-brown. In this way all details are clearly and 
beautifully brought out. 
With the view of contributing something toward the 
solution of the problem stated above, a study of the de- 
velopment of the sporogonium, especially the earlier stages, 
was made, together with that of the antheridia, to determine, 
if possible, whether the latter arise from an epidermal or 
a sub-epidermal cell. 
For the purpose of comparison, a similar study of Antho- 
ceros was carried on with that of Notothylas. 
The first divisions of the embryo correspond to those which 
regularly follow in all known Liver-worts. The fertilized egg 
is divided into an upper and a lower cell by the basal wall, 
which is at right angles to the long axis of the archegonium, 
the former becoming the capsule and the latter the foot of the 
sporogonium. Now follow two walls in rapid succession at 
right angles to the primary wall and to each other, thus 
dividing the embryo into eight cells disposed as the octants of 
a sphere. The exact order in which the two latter walls were 
formed was not determined. Fig. 1 represents three successive 
vertical sections of such an embryo, which include the whole 
of it. The eight nuclei were so situated that four came in the 
first section (a) and four in the third (e), while in the middle 
one (b) there were no nuclei. Serial sections of a similar 
embryo, at right angles to the archegonial axis, revealed 
similar structures. 
The embryo, however, is usually more oval in shape 
(Fig. 16). 
