ARCHEGONIUM AND SPOROPHYTE OF TREUBIA INSIGNIS 27 1 
cells can be perfectly explained as the result of a partial dissolution 
of the cell-walls, together with the rapid enlargement of the capsule 
in the later stages of development, which is not accompanied by a 
corresponding increase in the size of the spore mother-cells. 
Lack of material made it impossible to study the spore division, 
as no stages were found between that shown in figure 6, B, which shows 
the young spore mother-cells before the final divisions had begun, and 
nearly ripe spores. The material was fixed in acetic alcohol, so that 
the finer details of the nuclear structures were not very satisfactorily 
shown. The nuclear contents were often contracted, especially in 
the spore mother-cells; but whether this was a normal synapsis, or, 
what is more likely, the result of imperfect fixation, was not deter- 
mined. 
Griin succeeded in finding the dividing spore mother-cells, although 
not a sufficient number of stages to make out all the details. He 
found no indication of centrosomes such as Farmer^^^ describes for 
Pallavicinia decipiens, and some indications of which were found by 
the writer in Calycularia radiculosa. Griin found sixteen chromo- 
somes in the dividing cells of the sporogenous tissue before the final 
divisions of the spore mother-cells, but it is not clear just where the 
reduction division occurs. To judge from his account and figures, 
it seems that in Treubia insignis, as in Pallavicinia decipiens and 
Calycularia radiculosa, there is a "quadripolar " spindle, and not 
two successive bi-polar spindles such as usually are found in spore 
division. 
The calyptra (fig. i, C, cal.) enclosing the developing sporophyte 
is very large in Treubia, where it may reach a length of nearly 1.5 cm. 
and in also very massive. The surface develops scale-like outgrowths 
which give it a shaggy appearance, and among the scales may be seen 
the remains of the unfertilized archegonia. The fully developed 
sporophyte has a seta about 35 mm. in length and the ovoid capsule 
is about 2.5 mm. in length (fig. i, C). The capsule dehisces by four 
somewhat irregular valves (fig. i, D). 
Andreas^^ has given a fairly complete account of the structure of 
the wall of the mature capsule, and Griin has supplemented this by a 
careful study of the development of the wall in the later stages. 
Farmer, J. B. On Pallavicinia decipiens. Annals of Botany, 8. 1904. 
Andreas, J. Uber den Bau der Wand und die Offnungsweise des Lebermoos- 
sporogons. Flora 86. 1899. 
