80 MR. HOGG ON THE MODES OP 



vol. 48, part ii., p. 87, in proof of the ova being impregnated 

 before their deposition; but Ephemera (Mr. Fitzgibbon) very 

 shortly overturns this theory, in his beautiful edition of the same 

 work, p. 175, by expressing his surprise at the ' anatomical 

 ignorance' of Sir J. Hawkins, and by denying the existence of 

 external organs of generation in all river fish — a fact which must 

 be patent to every one. I trust, therefore, that no one will be 

 misled by Dr. Robertson, and I recommend all who may try 

 artificial breeding to be guided solely by the clear and clever 

 Ephemera.^ 



" Since the view here alluded to, and said to be supported by 

 Sir J. Hawkins, through a want of anatomical knowledge, is not 

 clearly detailed, I cite the passage itself from Isaak Walton's 

 immortal work, with Mr. Fitzgibbon's (Epliemerds) note to the 

 same, as published this year in that gentleman's edition of ' The 

 ComjDlete Angler:' — 



" Isaak Walton mentioning (chap, xiii.) * that Eels have all 

 parts fit for generation, like other fish, but so small as not to be 

 easily discovered by reason of their fatness ;' Sir John Hawkins 

 adds this note : — ' That fishes are furnished with parts fit for 

 generation cannot be doubted, since it is a common practice to 

 castrate them. See the method of doing it in Phil. Trans. ^ vol. 

 48, part ii. for the year 1754, p. 870. — H.' (Hawkins.) And 

 which note is continued thus by the Editor, or Ephemera: — [' I 

 am surprised at the anatomical ignorance of Sir J. Hawldns, 

 and at that of the writer in the Phil. Trans. No river fish have 

 external organs of generation, and cannot therefore be castrated. 

 Eels have ova and milt like other fresh-water fish, but in minute 

 portions.' — Ed.] P. 175. ' The Complete Angler, by Isaak 

 Walton and Charles Cotton,' edited by ' Ephemera^ (Fitzgibbon.) 

 Lond., 1853. 



" Now, with regard to Dr. Robertson's alleged experiment of 

 hatching the ova of female trout without having scattered, or de- 

 posited over them any milt from the male fish — if correctly given 

 in the ' Perth Courier,' as previously read by me — I can only 

 consider it to have been caused by one of the two following ways : 

 First., where the ova of the female trout had in some way received 



