282 ME. B. W. t. HOLT ON THE [-^pr. 19» 



fish or Miller's Tbumb, is one of the commonest fish in the 

 Plymouth district, and commences to spawn there, as has been 

 shown by Mr. S. D. Scott and myself ', in the first month of the 

 year. 



A number of females and small undiiFerentiated males were 

 successfully acclimatized in the autumn and early winter, but no 

 large differentiated males survived. However, two fine specimens 

 were brought in in January, and at once took kindly to their new 

 surroundings. When these males were placed in the tank a 

 female was observed to watch their movements with evident 

 interest. As frequently happens, they spent a considerable time 

 in swimming about the surface of the tank before descending. 

 The female meanwhile swam about at the bottom, following now 

 the movements of one male, now of the other. When one finally 

 descended, the female approached and appeared to smell him. 

 Her curiosity thus satisfied, she took no further notice of him. 



I had occasion to be absent from the Laboratory for about a 

 fortnight, ending on the 10th February. No signs of sexual 

 activity were previously observed, and Mr. Smith, the chief 

 Laboratory attendant, who was kind enough to keep watch on the 

 proceedings of the Dragonets during my absence, saw nothing 

 unusual in their behaviour. On the 11th February I found 

 pairing in full progress ; but, before giving the results of my own 

 observations, I propose to quote the account given by Savile Kent, 

 who, I believe, is the only writer who has dealt with the subject : — 



" The male, resplendent in his bridal livery, swims leisvu-ely round 

 the female, who is recliniug quietly on the sand, his opercula 

 distended, his glittering dorsal fins erect, and his every effort 

 being concentrated upon the endeavour to attract the attention 



and fascinate the affections of his mate The female, at 



first indifferent, becomes at length evidently dazzled by his re- 

 splendent attire and the persistency of his wooing. She rises to 

 meet him, the pair — so far as is practicable with fishes — rush into 

 each other's arms, and with their ventral areas closely applied 

 ascend perpendicularly towards the surface of the water. In con- 

 nection with these manoeuvres it may safely be predicted that the 

 ova are extruded and fertilized, but in the limited depth of water 

 of an aquarium tank the matrimonial tour cannot, apparently, be 

 sufficiently prolonged to ensure the consummation of this act ; the 

 fish, after reaching the surface, being projected by their previously 

 gained impetus slightly above it, when, falling apart, they sink 

 slowly to the bottom, and the process, after short intervals, is 

 repeated. It is, however, by no means impossible nor even 

 improbable that the fertilization of the eggs in Callionymus may 

 take place while the fish are above the surface of the water, as has 

 actually been recorded by Alexander Stenzel in the Nase or Zupe, 

 Ohonclrostoma ncmis." (Savile Kent, Handbk. Gt. Intern. Fish 

 Exhib. Lond., i. 1883, p. 128.) 



^ Holt and Scott, Joum. M. B. A., n. 8., v. p. 156, 1898. 



