4416 Fishes. 



the shanny ; but as development goes on the jaws are pushed out, the 

 belly is reduced in comparative size, and the dorsal and anal fins are 

 shortened, and become ultimately separated from the caudal. Thus, 

 in course of time, the young gradually assume the form and characters 

 of the parent. And there can be little doubt that this would have 

 been found to be the case with the young of the fifteen-spined stickle- 

 back, had Mr. Couch watched their development a little longer. The 

 obtuse form of the head, on which that gentleman places much stress, 

 is the embryonic condition of all fishes; the elongation of the jaws 

 is always an after-development. 



In conclusion, it may be remarked, that of the three or four other 

 species of fish described to nidify, one, a native of Demerara, is 

 stated to remain by the side of the nest with as much solicitude as the 

 hen guards her eggs ; the same is said respecting another species in- 

 habiting the Black Sea : but in none, so far as I am aware, has parental 

 attachment been observed to equal that evinced by the three-spined 

 stickleback. Yet we must not, therefore, conclude that it does not 

 exist to the same extent in others of the finny tribes. The habits of 

 these animals are very little known; and who can say what time may 

 bring to light respecting the economy of the inhabitants of the deeper 

 regions of the sea ! It is only, as it were, the other day that nothing 

 was known of the nidification of the three-spined stickleback, — a re- 

 sident of almost every pool, river and rivulet in the kingdom. 



P.S. — Since the above paper was read, I find I am wrong in as- 

 suming that Mr. J. Couch is the author of the Memoir on the Nidifi- 

 cation of the Fifteen-spined Stickleback, which was published in the 

 Transactions of the Royal Institution of Cornwall : this Memoir is, I 

 am informed, from the pen of Mr. R. Q. Couch, Not being able to 

 refer to these Transactions, I quoted from the * Illustrations of In- 

 stinct,' the work of the former gentleman, and in it the author's name 

 of the communication in question is not given. Mr. R. Q. Couch has 

 assured me that he still entertains the opinion he originally expressed, 

 that the nest described by him really belongs to the fifteen-spined 

 stickleback. 



I have also recently ascertained that, so far back as 1839, Dr. 

 Johnston described the nest of this fish, in the Transactions of the 

 Berwickshire Naturalists' Club. In the Doctor's communication it is 

 stated that " In an early volume of the ' Edinburgh Philosophical 

 Journal ' there is a slight notice of fishes' nests found on the coast of 

 Berwickshire, by Admiral Milne ; but the species of fish, by whom 



