84 LIVE LUNG-FISH AT THE ZOOLOGICAL GARDENS 
Nile system and the lakes connected with it. It was brought 
from the Victoria Nyanza by Mr. C. W. Woodhouse, Assistant 
Game Warden of East Africa. The species attains a length 
of between 4 and 5 feet, so that the specimen now at 
the Zoo is about half grown. The Gardens are not very well 
provided with aquaria, and the fish was turned out into the 
large tanks containing the two Australian lung-fish which 
have been there fifteen years, as this tank was the only one 
of which the temperature could be kept sufficiently high. The 
Protopterus, however, soon showed a vicious disposition, 
which made him an unsafe companion for the Ceratodus. The 
former is known to defend himself and his eggs with powerful 
bites. Although he has no upper jaw of the ordinary kind, 
he has large teeth on the lower jaw and on the roof of the 
mouth, and, according to Mr. Woodhouse, with these he can 
bite through a thick stick or bite a finger off. The fish had 
been carried all the way from Africa in mud, but in the warm 
water of the tank he soon became active, swimming about 
by means of undulations of the tail, and also moving over the 
gravel by alternate ‘ steps ’ of his slender pectoral fins, which 
are about 6 inches long. Before long, when his snout came 
near the tail of Ceratodus, he kept making vicious snaps, 
and it was decided that he must be removed, as there was 
evidently considerable risk of injury to the two large Australian 
fish which have been in the tank so long, and which showed 
no inclination at all to retaliate. Accordingly the small 
‘ Millions ’ fish were removed from a tank in the Tortoise House 
and Protopterus was put into that by himself. Protopterus 
differs strongly from Ceratodus in its round eel-like shape. 
It has a pair of lungs instead of one as in Ceratodus, and the 
living specimen went frequently to the surface for air. The 
scales are similar to those of Ceratodus, but covered by the 
skin, so that they are less distinct. The lines of the sense 
organs in the skin are very distinct and attract attention, 
namely, the lateral line down the side, the other curved lines 
on the head. One of the most curious points in the structure 
of the mouth is the presence of two pairs of nostrils, one pair 
in front and one behind, as in land animals, but both pairs are 
behind the upper lip.’ 
