NEST OF THE TEN-SPINED STICKLEBACK. 149 



larly-shaped pebble, which rested against the glass 

 side of the tank, enabling me to watch his move- 

 ments closely. He took great pains in his building 

 and interlaced the various portions of the structure 

 with great care. In about six days it was completed 

 and the ova deposited by females, the male playing 

 about them in the water, and performing the most 

 coquettish antics, while endeavouring to induce 

 them to enter the nest, and shed their spawn. The 

 young fish made their appearance in twelve days, 

 and were comparatively sluggish for the first part 

 of the time, remaining either upon or in the 

 immediate vicinity of the nest. On the fourteenth 

 day the male set about making another nest, 

 there being two females whose ova were not yet 

 ripe for exclusion. This second nest was formed 

 precisely in the same manner as the first, the male 

 dividing his time between the labour necessary for 

 its erection and the safety of the young brood 

 already hatched, which gave their respected father 

 infinite trouble, making him hunt them all over the 

 aquarium before returning to the nest, as they 

 generally did eventually. It is a very remarkable 

 fact, and one not previously noticed, to my belief, 

 that the male stickleback evinced as much anxiety 

 for the well-being of some young minnows (Cyp- 

 rinus phoxinus), also in the tank, as for his own 

 immediate progeny. The second nest was completed 



