268 EXPERIMENTS AND OBSERVATIONS 
body ; (2) in ova more advanced than the youngest the germinal 
vesicle has a number of nucleoli round its circumference within the 
membrane, and a granular mass in the centre ; the protoplasm of 
the ovum contains a round refringent body deeply stained in 
safranin, the vitelline nucleus; (3) in ova about ‘(06 mm. in dia- 
meter the vitelline nucleus has become elliptical in shape, and at its 
outer border isa larger rounded mass formed of a homogeneous sub- 
stance full of granulations; (4) the whole is transformed into a 
mass of granules, such as that observed im the ova of the majority 
of Teleosteans. The outer rounded body is described as formed by 
a modification of part of the refringent body, by a process of dis- 
integration which finally invades the whole of the latter, and transforms 
it into a mass of granules. Unfortunately Henneguy omits to state 
what is the condition of the yolk corresponding to these stages, and 
the only indication of the size of the eggs is that in stage 8 they 
are ‘06 mm. in diameter. 
My observations do not completely agree with Henneguy’s, but 
before pointing out the differences I wish to say something of the 
ovary. This organ in the pipe-fish is an elongated narrow cylindrical 
tube. There is one on each side of the body. It has a salmon- 
pink colour, due to the colour of the yolk in the eggs. The inner 
lining of the tube, the germinal tissue, only projects into the cavity 
of the tube in one fold or lamina, which is longitudinal. In this 
lamina alone are the young eggs formed, and they are pushed away 
from it as they become larger. 
A long series of stages of the developing ova can thus be studied 
in a single ovary, and the production of new ova seems to go on 
nearly all the year round,—at least, I have not yet seen evidence of 
a limited spawning season, and specimens with ripe ova or just spent 
have been opened by me from June to October. I believe that 
several batches of ova are produced in one season in succession, 
The number of ova produced is small, and, as is well known, they 
are received by the male into a skin pouch, and there hatched. 
It is not difficult to open the ovary and examine the proliferating 
lamina on a slide. In the fresh state the young yolkless ova are 
not very transparent, and it is impossible to make out any other 
structure than the germinal vesicle. But on the addition of dilute 
acetic acid the protoplasm of the eggs begins to coagulate, and in 
it there appears in most cases (Fig. 2) a single oval body, which 
in the smaller ova is in contact with the membrane of the germinal 
vesicle, in the larger is between it and the exterior of the egg. 
This body is of considerable size, both it and the nucleoli in the 
eerminal vesicle being relatively larger than in the egg of the flat- 
fish. Another peculiarity of this vitelline body is that it has a most 
