FISHES FROM MEXICO AND CENTRAL AMERICA. 
143 
season, they are said to be so fat that the curry made with them resembles that made with pork; but 
after swimming about for a few days, with their mouths full of eggs, they become dry and insipid. In 
bottle No. 2 you will see thirteen eggs, which I shook out with my own hands from the mouth of a fish 
8 or 9 inches long, each egg being about the size of a small grape. Preserved in that manner, viz, 
in glycerin, the eggs retain their natural color and transparency, whereas in spirit they soon become 
opaque. In the same bottle are some other eggs which were obtained by pressure, and which present 
the same remarkable difference in size as those in No. 1. You will perceive that these latter are per- 
fectly transparent, the smaller ones being scarcely visible, whereas those which were shaken out of the 
mouth of the fish contain a perfectly formed embryo and have a system of blood vessels spreading 
over their surface on one side. In bottle No. 3 you will see one of the eggs in a more advanced stage 
of development. Both the head and tail of the embryo have escaped from the egg, which, very little 
diminished in size, remains appended to the middle of the fish, giving it a very distorted appearance. 
1 ■ This adherence of the egg to the young fish after it has been hatched is not peculiar to this 
species. The same thing occurs in the case of the salmon fry, which are being produced, under the 
auspices of Mr. Buekland and other eminent pisciculturists, in such quantities as to give us some grounds 
for hoping that that delicious fish may become again so common in the rivers of England that it shall 
no longer be a luxury accessible only to the wealthy, and that farm laborers may again, as is said 
to have been formerly the case in the neighborhood of Newcastle, find it necessary to stipulate in 
their engagements with their employers that they shall not be fed on salmon on more than two days 
in the week. 
“This is the only specimen I was able to procure in that stage of development, the time not 
having then arrived for the general hatching of the eggs; but an intelligent friend, who is at Caltura at 
present, has promised to procure me other specimens, which will, I trust, enable me to ascertain a 
fact which I am inclined to believe, although I am not as yet prepared to assert it positively, namely, 
that the egg so appended is, in fact, the stomach of the animal in the state of enormous distention, 
and that, as its contents are absorbed while the other parts of the fish grow in size, it gradually 
assumes a more natural proportion to the rest of the body. To this conclusion I am led by observing 
the system of blood vessels, which is perceptible on the side of the egg opposite the embryo, and which 
certainly looks as if it was intended to form part of the organization of the future fish. I have since 
ascertained, by the aid of William Ondaatje, esq., assistant colonial surgeon, that the fish which carry 
the eggs, and subsequently the young fry, for so long a time in their mouths, are all males. 
“The name by which these fish are known to the natives is Anguluwa. They are regarded by 
them as all belonging to the same species, nor would an unscientific observer be likely to discover any 
specific difference between any of the specimens that I have seen; but having sent several specimens 
to F. Layard, esq., I received a letter from him in August last, in which he informed me that he had 
submitted the specimens which I sent him to Dr. Gunther, of the British Museum, who had ascertained 
that they belong to two distinct species, both new, of the genus Arius. Mr. Layard further tells me 
that the carrying of the ova in the mouth is not so novel a phenomenon as I supposed it to be, Dr. 
Gunther having described that peculiarity in the propagation of the genus Arius several years ago, 
from South American species.” 
It appears that the Rev. Bancroft Boake sent some of his specimens to the botanist, Dr. Greville, 
who in turn transmitted them to William Turner, who published the following account* concerning 
them: 
“The various plans resorted to by fish of depositing their ova, and protecting them during the 
period of incubation, have not infrequently attracted the attention of naturalists. One of the most 
curious and interesting observations made on this subject was brought before the Boston Society of 
Natural History about nine years ago, by Dr. Jeffries Wyman. He states! that when walking through 
the market of Paramaribo, in Dutch Guyana, he found the mouths of several species of Siluroid fish 
belonging to the genus Bagrus, or to one closely allied, distended with ova, sometimes between twenty 
and thirty in number. The eggs were in various stages of development, some recently deposited, 
*On a remarkable mode of gestation in an undescribed species of Arius (A. boakcii ) , by William Turner, M. B. 
(Lond.), F.R. S.E., senior demonstrator of anatomy, University of Edinburgh. <Journ. Anat. and Phys., vol. I, 1867, 
pp. 78-82. Beau before the British Association for the Advancement of Science, August 23, 1866. 
f Proceeding-' of Boston Society of Natural History, Sept. 15, 1857, and American Journal of Science, vol. lxxvi, 1859. 
