FISH BREEDING. 683 



On reading the foregoing contribution in manuscript, I deemed 

 the peculiar manner of the fecundation of the ova as discovered by 

 its author a matter of so much interest, that I handed it to a brother 

 angler, who is a microscopist, with a view of eliciting some remarks 

 on the phenomenon in reference to its bearing on the science of 

 biology. His observations and deductions appear so natural, and are 

 so reasonable, that I append them, with his accompanying note. 



My dear Nestor, 



I have read the manuscript on fish-breeding by your friend of 

 Niagara county, New York, with much pleasure, and herewith append 

 some observations referring to the aperture in the egg and the filament 

 of fecundating fluid which is observed to enter it. 



Yours truly, W. M. D. 



That there should be an air-bubble in a fish's egg, quite agrees with our 

 breakfast-table experiences on other eggs, and coincides with the boyish 

 knowledge gained by Easter picking of "butts" against "points" of the 

 splendid crimson and purple eggs, laid by our mothers' pet hens about 

 the end of Lent. But the novelty is, that, " in the shell of the egg cover- 

 ing this air-cavity, there is barely perceptible, with the aid of a glass, a 

 small orifice or hole," into which the spermatic animalcula which abou»ds 

 in the seminal fluid of all animals, and appearing under the microscope as 



animated commas, ' ' ' or incipient tadpoles with tales attenuated — 



> > > > 



called spermatozoa, and described in your article as " threads or filaments 

 projecting themselves from the mass of the milt, trembling and oscillating 

 in the water ;" finally to find their way to and into the air-chamber of 

 the egg, through the orifice described." I would here observe that the 

 spermatozoa of the Trout, being, from the nature of its parent fish, fishy, 

 would not voluntarily leap from its native element into the world of atmo- 

 spheric air contained in this great cavity ; as trouts, to satisfy hunger, 

 are not observed to chase grasshoppers about the pastures, or to tree the 

 ephemera or stone-fly — so I should not expect the embryo fish in the milt 

 of the male, of its own seeking, to venture into that air-cavity. And yet 

 I have no doubt that it finds its way through the orifice as observed by 

 your friend. The following query was started in my mind on reading his 

 observations: Is the egg a passive recipient of the spermatozoa, or is it 

 also living, and endowed with powers and instruments to attract, arrest, 



