702 PROFESSOR W. C. M‘INTOSH AND MR E. E. PRINCE ON 
LEREBOULLET, Kuprrer, Rreneck, and OELLACHER all noticed the accumulation of 
globules under the dise in impregnated ova ; and BAMBEKE (who quotes them) says these 
indicate food-particles for nourishing the germ. GERBE figures a crown of oil-globules 
around the periphery of the disc (No. 57, p. 330, pl. xii. figs. 3 and 4, b); while 
OELLACHER speaks of his lenticular germinal mass as including a lower layer which 
imprisons many oil-spheres, and at times is seen to be separated by a distinct contour 
from the disc. OELLACHER regards it as part of the blastodisc, and BAMBEKE likens 
it to his intermediary layer, though the subgerminal disc has been distinguished 
as a separate structure, neither to be confounded with the lower part of the germinal 
dise nor with the intermediary layer. LrrEBouLLEer indeed distinctly affirms that 
his mucous layer underlies, as a definite membrane, the blastoderm, while it rests 
upon the nutritive disc. BaMBexe erroneously likens his intermediary layer to this 
stratum beneath LEREBOULLET?’s mucous layer in the trout (No. 20a). In LereBouLLet’s 
view, three distinct strata must be recognised at the animal pole—(1) the germinal 
dise proper, (2) the mucous or intermediary layer, and (3) the “disque huileux” or 
nutritive layer. The separation of the stratum underneath the disc into two layers has 
caused some confusion, and the distinction is perhaps unnecessary. It is readily seen 
that the lower portion of the intermediary layer will be more fully charged with oily 
spherules and granules from the yolk than the portion in apposition to the base of the 
disc, but it is needless to separate it as a distinct oily stratum. A subgerminal stratum 
is probably not absent in any Teleostean ovum, though less prominently seen in some 
(e.g., Gadoids and Pleuronectids) than in others (sow and Gastrosteus), but the 
presence of a layer beneath the subgerminal stratum has been noted by very few 
observers. We cannot indeed regard LerEBout.et’s lowest (third) layer as separate from 
his mucous layer, which has been so generally recognised in Teleosteans. This single 
subgerminal layer, in whose lowest stratum oily spheres and granules are numerous, is the 
granular layer which Batrour speaks of, though in Elasmobranchs it consists chiefly of 
small yolk-spherules, and it is also G6rre’s floor of the germinal cavity (the 
“ Dotterzellen”). In Teleosteans it is continuous with the peripheral wall of protoplasm 
(His's “ Keimwall”) and the thin periblast beyond, originating in the same way, and 
persisting probably by continual renovation, the blastoderm thus feeding upon this 
finely granular layer. Kowatewsky regards the intermediary layer as a provisional organ 
(op. cit., 1886). We call by the name “subgerminal or nutritive disc” the disc-like 
stratum beneath the germ, and it embraces LEREBoULLET’s two layers—the mucous and 
the oily stratum; it is the thin central part of BAmprKe’s intermediary layer; it is 
OELLACHER’s inner layer, holding many oil-globules, of the “ Rindenschicht ;” and although 
OELLACHER speaks of it as more coarsely granular than the dise or layer above, yet 
it is derived from it. OxtiacnEr rightly compares his lower layer to LEREBOULLET’S 
mucous layer; while BamBerKe also correctly says that both are really his intermediary 
layer. 
We can therefore distinguish (with BamBexe) at the animal pole only two strata— 

