402 



SCIENCE. 



[N. S. Vol. VIII. No. 195. 



no food is taken and a tadpole changes into 

 a, toad within 3 daj's. We get a clue to ac- 

 tivity of life processes in transformation bj^ 

 weighing. A tadpole at maximum size 

 weighed 230 milligrams ; after hind legs 

 developed and food was no longer taken, 

 weighed 110 milligrams; two days later, 

 when tail is only 3 mm. long and the little 

 toad has crawled out into air, weight was 

 70 milligrams; less than J the weight of tad- 

 pole from which it developed. 



In man and other animals the proportion 

 of water is greater the younger the animal. 

 In a tadpole 91.6% of live weight is due to 

 water ; in the just transformed toad 88% is 

 water. The dry weight of a tadpole was 19 

 milligrams; of a transformed toad, 8 milli- 

 grams, less than half the dry weight of the 

 tadpole. There is, therefore, a great loss of 

 substance other than water in transforma- 

 tion of tadpoles into toads. In the growth 

 of the toad there is a steady increase from 

 egg to maximum of tadpole. During trans- 

 formation there is shrinkage. When the 

 little toad is ready to take food its progress 

 in size is i-apid, and in a few years it may 

 be 50,000 times as heavy as the egg from 

 which it came. 



On the Piscine Ancestors of the Amphibians. 

 By Professor Theo. Gill. 



A Historical Notice on Eoss' Eosy Gull, Eho- 

 dostethia rosea. By John Mtjedoch. 

 This species was discovered by Sir James 

 Eoss, in 1823, at Alagnak, Melville Penin- 

 sula. It was described by Eichardson in 

 1825. Up to 1881 only 14 specimens were 

 known, but from several localities. The 

 Point Barrow expedition (1881-93) found 

 them in large numbers, flying northeast 

 along the shore each autumn, and collected 

 a good series. The delicate pink of the 

 breast after death soon fades on exposure 

 to light. Fifteen additional specimens have 

 since been taken, all from the Arctic region 

 except one (Bering Id.). Nansen found 



them abundant in Juljr, near Hvitdenland 

 (81° 38' K). They undoubtedly breed 

 there, but the main breeding ground is 

 probably the land believed to be not far 

 north of Point Barrow. They probably al- 

 ways keep close to the loose edge of the ice- 

 pack. (To be published in full in the 

 Auk.) 



The Winter Food of the Chickadee. By Clar- 

 ence M. Weed. 



The paper records a study of the food of 

 the Black-capped Titmouse {Parus atricapil- 

 liis) during winter months. Forty-one 

 specimens were studied from November, 

 1897, to March, 1898. Eesults show that 

 this bird feeds on a large variety of insects. 

 The most striking item of food was eggs 

 of aphids, 21 per cent, of the whole. In- 

 sects as a class constituted 51 per cent., 

 spiders and their eggs 5 per cent., vege- 

 table matter 28 per cent. ; of this 20 per 

 cent, consisted of buds and bud scales, 

 introduced accidentally with aphid eggs; 

 indeterminable 10 per cent.; grit and other 

 extraneous matter 4 per cent. This study 

 yields additional evidence of the usefulness 

 of this familiar bird. 



A Eare Species of Whale. By Professor 



Alpheus Hyatt. 



The specimen came ashore on the beach 

 at Annisc^uam, Mass., August, 1898. The 

 specimen proves to be a species of Meso- 

 plodon, is 12 feet long, measuring along 

 the body. Two teeth, characteristic of the 

 genus, exist in the mid-length of the lower 

 jaw, but are small and not visible above the 

 gum. The only species known in the North 

 Atlantic is Mesoplodon bidens ; this specimen 

 is probably of that species. This species 

 has been recorded from European coasts, 

 but has been a very rare visitant of our 

 shores. 



Variations in Human Bones. By Dr. Thomas 

 Dwight. 

 A LECTURE delivered before the Zoolog- 



