402 
M. Oscar Schmidt’s Remarks upon 
cellina , and will be referable to the germ-layers of the pri¬ 
mary bud present in the larva.” These so-called primary 
buds have been seen in Loxosoma by all observers ; they are 
indicated by myself, Nitsche, and Vogt as genital foundations, 
by Salensky as “ buds.” They are very striking in Loxo¬ 
soma crassicauda , and still more so in L. pes. The name 
u primary bud” cannot be suitable, as in no case are the germ- 
layers as such contained in them, nor is the mesoderm of the 
future bud preformed in them. The simplest and most appro¬ 
priate expression still seems to me to be u germ-stock,” in 
case there is any objection to speaking of a “ bud-stock.” 
In the bud, the two bud-stocks, so soon as they have dis¬ 
tinctly separated from the mesodermic material, are always 
united by a median bridge. This may disappear in the adult 
animal. This, however, does not always happen, as I have 
seen clearly in one case in Loxosoma pes. In most cases the 
mature bud-germ-stocks are separated (see fig. 2, k). In our 
species they are characterized by a finely granular mass inter¬ 
vening between the cellular elements; and this causes the whole 
organ to appear as if darkly pigmented. When one is once 
convinced of the identity of the primary foundation in the 
bud with the organ k of the adult, one can no longer regard 
it as a somewhat hypertrophied part of the ectoderm. To the 
left of my figure, seen from the ventral side, the stage is shown 
in which a bud has been set free and a new one is not yet 
commenced. We see the greatly developed fold of skin which 
covers the bud-pit or bud-cavity. In the extent of this fold, 
of the pit, and the whole depression thereby caused, the species 
vary much from each other. No exposure ( Freiliegen ) of the 
umbilicus of the bud, such as Claparbde and Nitsche describe 
in Loxosoma Refersteinii, is observed in any of the other 
species. In L. raja the sinus, in which almost the whole 
mature bud finds its place, is bowl-shaped ; of course, as indeed 
my drawing shows, the inner angle of this bowl is covered. 
On the right side of our figure we see the decisive stage in 
which the germ-stock has given off a process externally, which 
will separate and furnish the foundation of a bud. I will and 
can only affirm this fact, without deciding whether one or several 
cells separate from the germ-stock, and without being able to 
state what is the signification of the hood of pale indistinct 
cells which is seated upon the process of the germ-stock. As 
to the main point, namely that the hud does not originate 
from one or more ectodermic cells of the mother , there cannot 
well be any doubt. It will now also become intelligible how 
I was misled by similar but indistinct images to my first erro¬ 
neous conception. Nitsche, who justly censures my u hide- 
