Neomeris dumetosa , L amour. 599 
cladaceae. That such a mode of formation of a multilocular 
gametangium is of biological significance, in allowing for the 
dispersal of these isolated gametangia in the resting condition, 
is quite conceivable, and the interpolation of this phase in the 
life-history must be regarded as a phenomenon of adaptation 
to environment, and in no way interfering with the sexual 
character of the parent plant. The peculiar phenomenon 
already mentioned as having been observed by Solms in the 
germination of Cympolia gametangia must hence be included 
under the head, not of apospory, but of apogamy. 
Returning to the consideration of N. dumetosa , it has already 
been observed that the transition from Stage III to Stage IV 
is startlingly sudden, and henceforth there is no apical recapi- 
tulation of previous stages. It is also to be noted that the 
cortical segments are again, not the second leaf-segments, but 
basal portions of these segments, as if the plan of structure 
which was worked out in the first segments had now been 
transferred bodily to the next further out. Possibly there is 
a gap in the record at this point ; at any rate, the immediate 
result of the arrangement, on the foregoing view of the nature 
of the reproductive organs, would be a doubling of the 
reproductive segments. Such a type in which the basiscopic 
cortical segment becomes reproductive, while the acroscopic 
remains sterile, thus combining in a single whorl the alternation 
characteristic of Halicoryne , is suggested even more strongly by 
Solms-Laubach’s figure of Polyphysa penicidus 1 , than the older 
drawings of Agardh and Cramer ; the sterile segment bearing 
a true whorl of three filaments. If Solms-Laubach’s view is 
correct, the Acetabidoides section may possibly be connected 
to the main series at this point, and may lead on ultimately to 
the Acetabulum type. I am however content to leave the 
discussion of the phylogeny of these types in the more 
competent hands of Graf zu Solms-Laubach, merely pointing 
out, as already indicated, the care required in dealing with 
septa as morphological landmarks. Thus, the septa which 
Solms-Laubach describes as cutting off the vestibules of 
1 Monograph, Plate II, Fig, 2. 
