POLYPTERUS. 17 



In an aquarium the Polypteri behave very peacefully towards one another ; never 

 have I observed them to bite their companions, even at feeding-time, which, however, 

 has never been a moment of great excitement. Probably owing to the insufficient 

 heat of the room in which the aquarium was kept, they did not at any time show- 

 great voracity, and often was the food offered them — worms, bits of raw meat, or fish — 

 left untouched. When the fish feels uncomfortable through having been long in 

 dirty water, the lower parts, the gill-membranes, the end of the snout, and sometimes 

 also the fins, become injected with blood and may assume a brilliant red coloration, 

 which gradually disappears when the water is changed. 



On a visit to Capt. Vipan's aquarium at Stibbington Hall, I had an opportunity of 

 observing again, at different times of day and night, the movements of P. senegalus ^ 

 and also those of P. lapradii. I was much struck by the different behaviour of the 

 two species — P. senegalus showing little shyness and being a good deal on the move, 

 whilst P. lapradii hides away among the weeds when under observation, moving 

 slowly on the bottom. Further, it was observed that the dorsal spines of P. lapradii 

 are nearly always erected, perfectly perpendicular to the axis of the body, when the 

 fish is resting, whilst they are folded down in P. senegalus. Neither Capt. Vipan nor 

 myself could see the spiracular flaps move, or air-bubbles escape from them. 



Eggs, ready to be deposited, are found in specimens measuring from 250 millim. 

 total length. These eggs are half black and half white, as in P. bichir, and measure 

 likewise about 1J millim. in diameter. 



On the expedition to the Niger Delta, where he contracted the fatal hsematuria to 

 which he succumbed on Jan. 19, 1904, Mr. Budgett saw his efforts at last rewarded 

 wiih success, and by artificially fertilizing the eggs he succeeded in bringing back to 

 Cambridge complete series for the working out of the development of this most 

 important type of Vertebrates, a task which he had already commenced when death 

 terminated his highly promising career. Writing from Southern Nigeria, Aug. 28th *, 

 he describes the segmentation as " astonishingly frog-like," and the larvae he showed 

 me at Cambridge shortly before his death appeared highly suggestive of even closer 

 affinity with the Batrachians than with the Dipneusti. 



The material left by Budgett is now being studied by Professor Graham Kerr, and 

 we are eagerly looking forward to the publication of his results. 



* < Nature,' lxviii. 1903, p. 516. 



