ANIMALCULE ALLIED TO NOTOMMATA. 
341 
sperm-bag is a fasciculus of muscular fibres (Plate XXXIV. fig. 14 B) which are inserted 
along the commencement of this evident 'penis, and over the latter organ the mem- 
branous sheath is reflected. Muscular bands arising from the tegumentary parietes 
of the animal, in the vicinity of the valvular opening, go to be inserted into the root 
of the penis (Plate XXXIV. fig. 14 A A), and may be frequently observed drawing it 
up to the opening, and even extending it beyond the body of the animal. Muscles 
also for the purpose of opening the valve (Plate XXXIV. fig. 14 EE), very similar to 
those for the same purpose in the female, and the bands which bring the penis forward, 
clearly show it to be an extrusory organ, and form a complete male apparatus. 
The sperm-bag evidently contains active spermatozoa (Plate XXXIV.fig. 13), having 
an oval flattened body (of a high refracting power), and a caudal appendage, that, 
while in the sac, is in constant vibratile movement ; they are somewhat larger than, 
and of the same general form as, human spermatozoa. 
I myself have never observed any action beyond the extrusion of the penis, but 
my friend Mr. Brightwell has observed in seven different instances the direct copula- 
tion of the two sexes. The following quotation from his notice of the fact in the 
Annals of Natural History for September 1848, clearly demonstrates this important 
circumstance. 
“ Observations as to the Union between the Sexes. 
“June 15th. — Placed a male and six females in a small glass trough by themselves, 
and two males and about thirty females in a large trough. 
“June 16th, between 7 and 8 a.m. — On examining the small trough observed that 
the male on approaching one of the females attached himself to its side by the sper- 
matozoid projection, and remained so attached from twenty to thirty seconds. The 
same male acted precisely in the same manner with four other females. These five 
connexions took place in about fifteen minutes. 
“At 5 p.M. — Saw one of the males in the larger trough attach himself to a young 
one of the other sex for about twenty seconds, and afterwards to a full-grown female 
for a somewhat longer time. Saw this last connexion in a clear light most distinctly. 
The end of the sperm-tube was attached to the side of the female, and the rest of the 
body of the male was quite free. Saw the same male soon after fix itself by its head 
to the glass and remain so for thirty seconds, and during this time it continued 
puffing out and drawing in the sides of its body as if to give them their utmost dila- 
tation. 
“June 20th, 5 p.m. — Placed a young female and a male in a trough by themselves 
and watched them very frequently till eleven at night, and though they came very 
near each other no conjunction took place. 
“June 21st, 8 a.m. — Found the female dead and the male alive. Put three other 
females to this male, and in a few minutes saw the male as soon as he approached 
one of the females attach his sperm-tube to its side and remain so attached fifty 
2 Y 
MDCCCXLIX. 
