794 MR EDWARD J. BLES ON THE 
observations then made has already been published (Buzs, 01). Since then the same 
female has spawned during the spring and summer of 1901, 1902, and 1903, under 
conditions easily established anywhere. The methods adopted are possibly more or 
less applicable to the breeding of other Amphibia in confinement, and I will therefore 
enter into details. 
In the first place, the most necessary condition of success in this and similar cases 
is that the frogs should be allowed to hibernate. But, in order to accomplish this suc- 
cessfully, a frog must be in the best health and condition when the winter sets in, and 
must have passed the summer in the best circumstances as regards heat, light, and 
food supply. 
—= 
C | 2 4 
Text Fic. 2.—Tropical Aquarium described in 
text. The diameter of the bell-jar is 20 
inches ; other parts are in proportion. 
Xenopus is practically a purely aquatic animal, probably more so than any caduci- 
branchiate Urodele, and should be kept in an aquarium at a tropical heat during the 
summer in a place which is reached by the early morning or the evening sunshine. The 
direct rays from the sun will thus not strike the aquarium for more than an hour or so. 
The form of tropical aquarium I have found perfectly successful is one devised by my 
friend the late Mr J. 8. Bupcerr, who kindly gave me permission to describe it here. 
Text fig. 2 shows a bell-jar 20 inches in diameter standing on an iron tripod. 
The circular ring at the top of the tripod is slightly dished inwards to adapt it to the 
bottom of the bell-jar. Upon the upper surface of this ring rests the flange of a 
galvanised iron tank containing water, and heated below by a Zeiss micro-burner 
(Bunsen), This tank acts as a water-bath, and is kept 10°-15° C. hotter than the 
aquarium, according to the quantity of water in the latter. I find that this particular 
