262 MR. NEWPORT ON THE IMPREGNATION OF THE OVUM IN THE AMPHIBIA 



having passed, and the function being fulfilled. Thus too, I have noticed that, when 

 from accident, but more especially when from reduction of the temperature in the 

 surrounding medium, the season of spawning has been greatly retarded, the impreg- 

 nating power of the male is much diminished, and perhaps is almost exhausted, 

 through constant shedding of the spermatic fluid, which, I have found, often takes 

 place when the oviposition of the female is delayed, and the individuals are disturbed 

 or interfered with. The female is then forsaken by her partner, and when this occurs 

 it rarely happens that the connubial intercourse of these two individuals is recom- 

 menced. When this separation has taken place, there is usually but a small quantity 

 of fluid remaining in the male organs, and even in that, the number of spermatozoa 

 is considerably diminished, and their power of motion is exceedingly feeble ; while the 

 quantity of molecules and cells is increased. When several days, or a week or two 

 have elapsed, there are not only fewer spermatozoa, but those which remain are 

 much more feeble in action. This is exactly what occurs also in the Toad. On the 

 sixth of June I found that the testes and efferential ducts in a male Toad, which had 

 been kept from pairing during the whole season, were still filled with spermatozoa, 

 together with a very small quantity of liquor seminis with active molecules moving 

 in it ; but that, though the spermatozoa were in full abundance, nearly the whole of 

 them were entirely motionless, while the motions of the few which still gave evidences 

 of vitality, were exceedingly feeble, whether the spermatozoa were examined simply 

 in the fluid portion of the semen, or whether they were mixed with water, in which, 

 as is well known, the motions are always at first greatly increased. 



A similar reduction in the number of the spermatozoa and diminution of their 

 motive power, appears to exist in animals which have become exhausted through long 

 confinement or want of food ; at least, if we may so judge, from a few observations 

 on the Tritons. A Triton palustris, which had been captured on the seventh of May, 

 and accidentally confined without food till the sixth of June, was examined immediately 

 after death. The efferential ducts were well-filled with spermatozoa contained in a 

 distinctly perceptible quantity of liquor seminis. When the spermatozoa were ex- 

 amined, without the addition of water, their motions were regular, but apparently 

 very much slower than usual, being uniform and undulating, without that peculiar 

 rapid ciliary action of the spirally twisted tail, which is so constantly referred to as 

 characteristic of the spermatozoa of the Tritons and of some other Amphibia. When 

 water was added, the motions were immediately accelerated, and the tail, which 

 before was merely flexed, and almost longitudinally extended from the body, became 

 folded and entwined around it, and its rapid ciliary movements were commenced. 

 But these gradually subsided within a very few minutes. In another specimen, which 

 had been captured at the same time as the preceding, and confined under similar 

 circumstances, but which, at the time of examination, had been already dead for 

 more than twenty-four hours, scarcely any spermatozoa remained in the testes, or in 

 the efferential ducts. There was a great quantity of cells, with granular nuclei, in 



