DEVELOPMENT AND LIFE-HISTORIES OF TELEOSTEAN FISHES. 789 
effected. There is, at an early stage, no true dermis beneath the Malpighian layer. 
Poucuer speaks of this subepidermal tissue as a soft variety of laminated tissue, having 
a very loose texture, and therefore little firmness (No. 119, p. 291), but in its earliest con- 
dition it is simply a soft semifluid stratum in which amorphous matter abundantly occurs. 
In this layer pigment develops (pt, Pl. IV. figs. 13, 20), and always appears as definite 
amorphous corpuscles, not a mere diffused solution. 
In different species the early coloration shows very distinctive features, the colour of 
the pigment and its distribution being, in fact, so striking as to afford aid in diagnosis. 
In some species the pigment is confined to the embryonic trunk (PI. V. fig. 2); in 
others it extends over the extra-embryonic layer, 7.¢., the yolk-sac (Pl. XVI. figs. 2, 8). 
Certain forms, again, exhibit one kind of pigment (Pl. XVII. fig. 1; Pl. XIX. fig. 8); others 
show two or more colours in the larval stages (Pl. XVI. figs. 1, 3, 5-9). No generalisation 
can be made, for in the same genus closely allied species show great diversity in these 
respects. Usually the pigment occurs in the form of minute isolated spots scattered 
upon the dorsum, and visible within one or two days after the closure of the blastopore ; 
though it frequently forms superficial protuberances, evidently pushing out the epi- 
dermal stratum at certain points. The form of the corpuscles undergoes rapid changes ; 
thus in a larval cod under examination two spots at the anterior border of the liver were 
seen to be finely branched, but before a sketch could be completed they visibly altered, 
and presented a simple rounded aspect. 
In the cod (Pl. XIX. fig. 8) and haddock (Pl. XVII. fig. 1) black spots only occur. In 
the ova of the former species, seven days after fertilisation, these spots, amorphous or 
rounded in form, were scattered sparsely over the dorsum and lateral regions, but in a 
few days they multiplied and extended from the snout to the tip of the tail, without any 
regular disposition. In larve of the cod, soon after emerging, however, a further change 
in the distribution of the pigment takes place, for the spots, which are now elaborately 
stellate, become aggregated in four distinct bands (Pl. XIX. fig. 8), two very dense 
broad bands—a pectoral and an abdominal—occurring on the trunk proper; while 
the tail exhibits two less dense bands, and often indications of a third. The haddock 
never shows this regular series of dark bands, which seem to be so characteristic in the 
newly emerged cod. In the ova of the haddock on the eighth day (two days after 
closure of the blastopore), black spots are irregularly dotted over the dorso-lateral 
regions, and subsequent changes chiefly affect the number and form of the spots. A 
larva two days after emerging shows stellate spots of the most elaborate form, which 

send out complex ramifying processes. These spots appear on the cranial region, and 
very thickly in the post-otocystic and lateral regions of the trunk proper.  Posteriorly 
they are chiefly confined to the lower half of the caudal trunk, only two or three large 
spots occurring above the level of the notochord. Occasionally one or two spots are 
seen to send processes into the fin-membrane. The whiting offers a great contrast to the 
foregoing Gadoids, since on the eighth day (three days after the closure of the blastopore) 
very faint yellow spots appear, and are thickly distributed over the entire trunk, including 
