September, 1911. 



KNOWLEDGE. 



359 



appears greater than would be accounted for by the presence 

 of other radio-active substances such as uranium, thorium and 

 actinium, and might perhaps be due to the more complete 

 absorption of the radium rays in the mass of the pitchblende, 

 than occurs when a measurement of the heat production of 

 pure radium is made. 



ZOOLOGY. 



By Professor J. Arthur Thomson. M.A. 



THE AW.AKENIXG HEDGEHOG:— When a hibernating 

 hedgehog awal<ens it rapidly warms itself up. Whether this 

 comes about automatically, or whether it is due to the 

 awakening animal "pulling itself together" seems to be a 

 moot point. The fact is that the animal rapidly warms itself 

 up. The chemistry of this, according to Tanzo Yoshida and 

 Ernst Weinland, is a rapid combustion of glycogen along with 

 a small or moderate quantity of fat. There seems no doubt 

 that the important fuel that so rapidly makes the fire of life 

 burn up is glycogen: the fat is only subsidiary. It must be 

 noticed that in the hedgehog the awakening and the warming- 

 up are two distinct, though associated, processes ; for the 

 animal maybe wide awake at a lower temperature. 



VARIATIONS IN FOWLS' COMBS.— Poultry-breeders 

 know when a hen is going to begin to lay by a rapid and 

 marked increase in the size of the comb. Mr. Geoffrey Smith 

 has shown that this correspondence is exact both in young 

 and adult hens. There may be an increase of 130 per cent, 

 within three weeks, and this does not correspond with a 

 general increase in weight, though the latter usually precedes 

 it. After the laying period, there is a decrease in the comb 

 The cock's comb does not exhibit these marked fluctuations. 



The increase is due to a fatty infiltration of the central 

 connective-tissue core of the comb, and the explanation of the 

 infiltration is to be found in the fact that at the egg-laying 

 periods the blood becomes charged with fatty material which 

 is conveyed to the ovary for the formation of yolk, the excess 

 being deposited in the comb, and probably in other situations. 

 Mr. Geoffrey Smith compares this with what occurs in a 

 spider-crab parasitised by Sacciiliiia ; the Saccidiiia " forces 

 the crabs to elaborate yolk-material ;" this circulates in the 

 blood ; it should be stored in the ovaries, but there are none, 

 because of the inhibiting influence of the SacciiliiKj, the yolk 

 material : it nevertheless acts as the stimulus for the develop- 

 ment of the adult female secondary sexual characters. 



HORNBILL'S STOMACH.— Everyone knows of the 

 strange bag of indigestible debris which hornbills periodically 

 eject, but there is a lack of precision in the statements that 

 have been made. An interesting recent contribution by H. C. 

 Curl shows that the deciduous membrane in the great 

 Philippine hornbill. Hydrocorax Uydrocorax, studied outside 

 the breeding season, is a tough, homogeneous sac formed of 

 colloid material secreted by the glands of the stomach wall. 



MOSQUITO SUCKED BY MIDGE.— F. H. Gravely 

 reports finding in the Sunderbunds a small Chironomid fly 

 iCiilicoidcs) with its proboscis well-embedded in the abdomen 

 of a mosquito ^Myzontyia rossii} and evidently imbibing 



nourishment from it. Probably the Culicoides sucks 

 mammalian blood, and was taking it second-hand from the 

 mosquito. 



A FRESHWATER RHIZOCEPHALOX.— Dr. Nelson 

 Annandale, Superintendent of the Indian Museum, describes a 

 very interesting animal, which he calls Sesannaxcuos 

 Dionticola g. et sp. n. It is somewhat like the well-known 

 SaccuUiia that occurs beneath the abdomen in shore crabs, 

 and it occurred in a similar position on a fresh water crab, 

 Scsanna thelxiiioc. in a jungle stream in the Andamans, 

 seven hundred feet abo\'e sea level. This is the only known 

 freshwater Rhizocephalon, and only the one specimen has 

 been found. 



CAMBRIAN SEA-CUCUMBERS. — From the Middle 

 Cambrian, British Columbia. Charles D. Walcott describes 

 the first Holothuroids found as fossils. Some isolated 

 calcareous plates have been previously recorded, but now we 

 have entire animals. — unluckily without any calcareous plates. 

 The most remarkable type, which the discoverer calls Etdonia. 

 and describes as free-swimming, has some suggestion of a 

 medusa about it, but Dr. Walcott has given careful con- 

 sideration to that possibility. Trilobites, Phyllopods. and 

 Medusae were found in the near vicinity. .Again, we have 

 striking evidence that there must have been great steps in 

 animal evolution in PreCambrian and early Cambrian ages. 



NOTES ON THE AFRICAN FRESHWATER 

 MEDUSOID L/.17A'0CiV/D^.— Charles L. Boulenger has 

 some interesting notes on this medusoid from Lake 

 Tanganyika. The stinging-cells of the tentacles are not 

 developed in situ, but in the ectoderm of the " nettle-ring," 

 a thickening along the margin of the umbrella. This ring is a 

 factory and a storage- place of the stinging-cells and they 

 migrate thence to the tentacular batteries. There is a well- 

 developed double nerve-ring at the base of the velum, similar 

 in most respects to that of Liiniiocodiuin, and of other 

 medusoids. Mr. Boulenger shows that the manubrium is 

 undoubtedly functional as a digestive organ. The develop- 

 ment of the medusoid buds presents se\eral interesting features, 

 some of which are undoubtedly primitive. 



A RE.MARKABLE SPONGE.— Mr. R. Kirkpatrick. of the 

 British Museum, gives a full and finely illustrated account of 

 Mcrlia nonnani. a sponge with a siliceous and calcareous 

 skeleton. It w^as found by Canon Norman, and subsequently 

 by Mr. Kirkpatrick, in sixty to ninety fathoms, off Madeira and 

 Porto Santo. The sponge character of the organism has 

 been called in question mainly, if not wholly, on a priori 

 grounds, but the author has examined five hundred specimens. 

 Dr. Weltner supposes that the calcareous structure is that of 

 an unknown organism in which a siliceous sponge has settled. 

 " If this be so," Mr. Kirkpatrick answers. " the said organism 

 has preserved its incognito in a marvellous manner." But we 

 do not follow his reasoning when he says : " If. as I believe, 

 Mcrlia is a siliceous sponge which has taken to forming a 

 calcareous skeleton, then this sponge furnishes a good example 

 of the hereditary transmission of an acquired character." 

 Taking to forming lime is not an " acquired character " in 

 the technical sense ; it was probably a constitutional variation. 



THE BRITISH A.SSOCIATION. 



This year's meeting will open on Wednesday, August 30th. at 

 Portsmouth, under the presidency of Professor Sir William 

 Ramsay, who will give his address in the Town Hall at 

 8.30 p.m. The Hampshire Post estimates that between 

 fifteen hundred and two thousand members will be present. 

 On Friday, September 1st, at 8.30 p.m.. the first Evening 

 Discourse will be delivered by Dr. Leonard Hill. F.R.S.. 

 on '■ The Physiology of Submarine Work." On Monday, 

 September 4th, at 8.30 p.m., the second Evening Dis- 

 course will be delivered by Professor A. C. Seward, M.A., 

 F.R.S., on " Links with the Past in the Plant World." 



Of recent years there has been an outcry against the 

 papers being made so technical that local members, who 

 are not specialists, cannot appreciate them. It has been 

 customary for Section D (Zoology I to arrange a popular 

 lecture, and this year two appear in the programme, namely, 

 one on " Fairy Flies," by Mr. Fred Enock, and the other on 

 " Fossil Reptiles,'' by Dr. Andrews. "Rain" will be considered 

 by Dr. H. R. Mill in his lecture to the operative classes, and 

 some very attractive excursions have been arranged to 

 -Arundel Castle, to the New Forest, and to the Isle of 

 Wight. 



