ON HEEL-rADS IN YOUNG TOUCAJSET. 1095 



to the rjvpid growth of the young. When Dr. Spni-rell captured 

 the mother, the little ones were still in the pouch. Six weeks 

 afterwaids, when they reached the Gardens, they had left the 

 pouch for good, were about one-fourth grown, and were just 

 beginning to feed on their own account, though mainly dependent 

 upon their mother's milk. In another six weeks — that is to saj, 

 three months after capture — they were three-fourths their 

 mother's size, and apparently quite capable of fending for 

 themselves. 



Mr. PococK also exhibited two young examples of a Degu 

 (Octodon degus), born from a pair from Valparaiso, presented by 

 Mr. Walter Goodfellow, F.Z.S. The mother had a litter of four, 

 but died from inability to give birth to a fifth. The little ones 

 were fed by hand, aiid although two of them quickly died from 

 pneumonia, the remaining two throve and promised to do well. 

 Like the young of all Hystricomorphous rodents, the J3egus are 

 of large size at birth and open their eyes within twenty-four 

 hours, and are in every i-espect very precocious as compared with 

 young rats. Particular attention was directed to the lateral 

 position of the teats in the Degu, a condition which is repeated 

 in the Viscacha and Chinchilla and the Coypu. This condition 

 is probably an adaptation to the large size of the young, which are 

 enabled to suck lying alongside the mother, so that they do not 

 interfere with each other. In the Coypu, as first described by 

 Owen, the teats are higher up the side than in the Chinchilla and 

 the Degu, an arrangement which permits the young of that 

 specieSj it has been alleged, to suck while swimming alongside 

 their mother in the water. 



Heel-Fads in young Toucanet. 



Mr. D. Seth-Smith. F.Z.S., Curator of Birds, exhibited a 

 spirit-specimen of a young Toucanet {Selenidera maculirostris) 

 (text-fig. 191) which had been hatched in the Society's Gardens 

 in July, and called special attention to the well -developed serrated 

 pads on the back of the ankle-joint or heel. This pad had been 

 previously observed in the nestlings of Woodpeckers, Wrynecks, 

 and Barbets, and it was only to be expected that it would be 

 present also in the Toucans. 



The use of this serrated pad, which disappears soon after the 

 young bird leaves the nest, is doubtless to enable it to climb up 

 the side of the hollow cavity in a tree in which it is hatched — 

 these pads forming, as it were, a second set of claws. It is note- 

 worthy that no such pads are found in the Parrots, which nest 

 in similar situations to those chosen by Barbets and Toucans, but 

 which are provided with a hooked beak w^hich aids them in 

 climbing. 



