October 25, 1901.] 



SCIENCE. 



639 



ley Gardiner gave an account, illustrated 

 by excellent lantern slides, of his observa- 

 tions upon the coral islands of the Mal- 

 dives, the evidence obtained seeming to in- 

 dicate that they had been formed during a 

 period of elevation. Dr. J. Y. Simpson 

 gave the results of his observations 

 on the occurrence of variation in binary 

 fission. It has been generally accepted 

 that this method of reproduction is merely 

 a duplication and that variation does not 

 occur in connection with it, but only as 

 the result of a commingling of the chro- 

 matin of two individuals in conjugation. 

 Testing this generalization by observation 

 of successive generations of Paramoecium 

 and Stylonychia, it was found that varia- 

 tion may accompanj'^ fission, modifications 

 occurring in the general outline of the 

 body, in its total length, in its greatest 

 breadth, in the distance between the con- 

 tractile vacuoles of Paramoecium and in the 

 length of the median caudal bristle of Sty- 

 lonychia. From the fact that such variations 

 do occur and may be transmitted to the 

 succeeding generation, it would seem that 

 fission is the primary method of reproduc- 

 tion among the Ciliate Infusoria, and that 

 conjugation is merely a method of compen- 

 sating for the waste involved in that process. 

 The President of the Section gave some 

 observations, additional to those contained 

 in his address and illustrated by lantern 

 slides, on zebras and zebra-hybrids. He 

 pointed out that the stripes of the zebra were 

 undoubtedly protective, causing the animal 

 to become indistinguishable at a compara- 

 tively short distance, and he was able to 

 render a dun-colored pony similarly indis- 

 tinguishable by tying ribbons upon it so as 

 to break up the uniform coloration. The 

 lion is the most inveterate enemy of the 

 zebra, which is protected by its coloration 

 as well as by the rapidity of its movements, 

 for there is no animal which the author 

 knew which could turn about and break 



into a trot so quickly as the zebra. As to 

 the original nature of the coloration of the 

 zebra, it was pointed out that although the 

 forms such as the Chapman zebra, which 

 were less striped, might be supposed to be 

 most primitive, yet it was an interesting 

 fact that zebra-donkey hybrids were more 

 richly striped than pure-bred zebras. 



Professor W. E. Hoyle described an in- 

 teresting sub-pallial luminous organ in cer- 

 tain forms of Cephalopods, and Mr. J. 

 Graham Kerr read a suggestive paper on 

 the ' Origin of the Limbs of Vertebrates,' 

 in which, after pointing out the unsatisfac- 

 tory nature of the theories at present ex- 

 istent, he suggested the possibility of the 

 limbs being derived for external branchiae, 

 such as are found in Polypterus and in cer- 

 tain Urodele amphibians. It may be stated, 

 however, that from the discussion which 

 followed, the new suggestion did not seem 

 to be received with any great amount of 

 favor. Major Ronald Eoss gave an account 

 of the experiments on the destruction of 

 the mosquito now being carried on in Sierra 

 Leone by the Liverpool School of Tropical 

 Medicine, and stated that although the ex- 

 periments had been in progress now for 

 only two or three months, yet there was 

 already an appreciable diminution in the 

 numbers of the insects, and maintained that 

 it is possible that even on the west coast 

 of Africa, malaria may become a thing of 

 the past. 



Other papers presented to the Sec- 

 tion were ' The Pelvic Cavity of the Por- 

 poise as a Guide to the Determination 

 of the Sacral Region in the Cetacea,' by 

 Drs. Hepburn and Watson ; ' The Rela- 

 tionship of the Premaxilla in Bears,' by 

 Professor R. J. Anderson ; ' A Method of 

 Recording Local Faunas,' by Mr. E. J. 

 Bles ; ' The Fishes of the Coats Arctic 

 Expedition,' and ' A Preliminary Notice of 

 the Fauna of Franz Joseph Land,' by Mr. 

 W. S. Bruce ; ' The Behavior of Artifi- 



