124 Papers from the Department of Marine Biology. 
No. 6 of the table, represented in external view in figure 3 of plate 2 
and in longitudinal horizontal section in figure 4 of plate 3, contained 
46 eggs. Specimen No. 8 of the table, the largest ovary examined, 
contained only 12 grown eggs in the right sac and 13 in the left. 
This ovary, for which, unfortunately, no date of capture can be given, 
since the label has gone to pieces, was, notwithstanding its great size, 
plainly not ripe. In the right sac were about 20 and in the left about 
25 eggs of 10 to 12 mm. in diameter. This tends to confirm the idea 
previously expressed that there may be more than one egg-laying in a 
season. If all these eggs were laid in one season, this ovary would have 
a productive capacity of about 70 eggs. 
Ovary No. 2 of the table contained 46 fully grown eggs, while No. 3 
gave up 55. However, it is probable that these figures do not repre- 
sent the maximum. Only one live specimen was studied. A female 
taken May 27, 1909, was kept in a tank for 4 days. She was then 
spawned and forced to give up 68 of these huge eggs. This is the 
largest number of grown eggs I have ever obtained from one fish and 
is probably the maximum number found in the ovary of any female 
gaff-topsail catfish. 
HISTORICAL ACCOUNTS. 
It is surprising to find how little is known about the structure of the 
ovary of any catfish. So far as the writer knows, no real investigation 
of this interesting organ has ever been made, and the data now to be 
presented have been noted by various writers as merely incidental in 
the course of other investigations on catfishes. As to the ovary of the 
gaff-topsail, the only two known references will now be briefly con- 
sidered, and after that the strictly chronological order will be adhered 
to. In 18848. C. Clarke wrote: ‘“‘The eggs of this species are golden 
yellow, and of the size of grapes, which they much resemble, in bunches 
of ten or twelve.”’ And again in 1892, ‘‘He slashed it [the gaff-top- 
sail] open with his knife, bringing out a bunch of eggs in form and 
color like golden grapes.”’ In this connection the attention of the 
reader is called to figure 6, plate 4. 
The oldest direct reference to the ovary of the catfish, which has 
been found so far, is by Bonnaterre in 1788. He speaks of the eggs of 
Silurus ascite as being ‘‘disposed on each side of the abdomen in two 
packages [ovisacs?], which extend from the diaphragm clear back to the 
anus.” If his brief description is referred to figure 3 of plate 2, of this 
paper, it will be seen how accurately he wrote 130 years ago. 
Next to Bonnaterre, our oldest and most numerous references (for 
there are no less than 14) are from the Austrian ichthyologist, Rudolph 
Kner. Writing of Siluride from Brazil, in 1858, he gives the interesting 
data cited below, together with the only known figure of the ovary of a 
catfish. Of Arius luniscutis Cuvier and Valenciennes, he says: 
