1886. | Embryology. l 79 
The paired spinal nerves which pass to the pelvic fins are caused 
to cross those passing to the pectorals, because of the sudden 
translocation of the former pair of fins already alluded to. 
It has also been stated by authors that Batrachus possesses no 
lateral line. This isan error, for the writer found that the neuro- 
mastic grooves or furrows, which remain open for a considerable 
time on the heads of the larve, are continued into a lateral line 
system on the sides, a condition of things which is also very evi- 
dent in the adult, if the latter is carefully examined. There are 
also series of efferent pores present in the adults. The lateral 
neuromastic canal bifurcates in the vicinity of the shoulder-girdle 
and sends a dorsal branch backward below the base of the dorsal, 
and a ventral branch above the base of the anal. These two canals 
run nearly parallel along either side of the body and even extend 
backward upon the tail, as shown by some fine preparations of the 
skin of the embyro mounted by Professor Libbey, of Princeton. 
Another point of some interest is the fact that the entire brood 
of young embryos upon any one stone have their heads directed 
one way and toward the light, which comes in at one side of the 
little retreat prepared by the adults. This is very remarkable and 
seems to indicate that the direction whence the light comes has 
some influence in determining the direction in which the embry- 
onic axis will be formed in the blastoderm. 
Which in the first place caused the egg-membrane to adhere, is not 
Soluble in water, 
The yolk is peculiarly homogeneous and does not readily coag- 
ulate or harden in the presence of ordinary reagents, such as 
chromic acid, as long as the egg-membrane is intact. There are 
no oil-drops present and the ova are much heavier than their own 
volume of sea-water. The number of ova found in one brood 
varies considerably, but it does not seem that there are ordinarily 
much over two hundred laid in one place. They are dirty-yellow 
color and very firm to the touch, with a very narrow space be- 
tween the vitellus and enveloping egg-membrane. : 
The development of the toad-fish is peculiar, if not unique, in 
Presenting a prolonged fixed stage after the period of hatching or 
escape from the egg-membrane is over, during which all or nearly 
all of the yolk is absorbed. The embryo is therefore finally set — 
si without being encumbered by a heavy yolk, such as is met 
in the embryos of the salmon. Such a provision obviously 
has its advantages, especially since the young are also guarded by 
© male parent during the period of their helpless fixation. - One 
