232 THE ZOOLOGIST. 



SCIENTIFIC SOCIETIES. 



Linnean Society of London. 



May 3rd, 1894. — Prof. Stewart, President, in the chair. 



Mr. J. H. Burkill was admitted, and Dr. Johann Mueller, of Aargau, 

 and Prof. K. Mitsukuri, of the University of Tokyo, were elected Foreign 

 Members of the Society. 



Prof. Poulton exhibited the .larvae of certain Lepidoptera to illustrate the 

 results of experiments which he had made in regard to the influence of 

 environment upon their colours. Variously coloured twigs and shoots, such 

 as occur in nature, were shown to influence the appearance of many twig-like 

 larvae in such a manner as to aid their concealment. Commenting upon 

 this exhibition, Mr. A. E. Gibbs detailed the results of feeding the larvae 

 of Amphidasys betularia on birch which has brown shining stems, and on 

 an acacia the petals of which are of a green colour, the larvae in these 

 cases being brown and green respectively. 



Prof. G. B. Howes exhibited and made remarks upon the eggs and 

 young of Ceratodus fosteri, received from Prof. Semon, of Jena, who is 

 engaged in working out the development of this fish. Prof. Howes also 

 exhibited a specimen of Lepidosiren paradoxa, an extremely rare fish in 

 collections, from the backwaters of the Upper Rio Paraguay, and made 

 remarks upon its anatomy. 



Mr. James Saunders, of Luton, with the aid of the oxyhydrogen lantern, 

 exhibited Plasmodium in the act of forming sporangia. The species, which 

 had been found on birch, was Didymium squamulosum. 



On behalf of Dr. H. B. Guppy, the Secretary read a paper on the habits 

 of three species of Lemna. In this paper, the author detailed the results 

 of experiments made by him during a period of twenty months, and showed 

 that Lemna gibba can pass the winter either in the gibbous form, or with 

 fronds which in appearance come to resemble those of Lemna minor. The 

 flowering of Lemna gibba was observed in July, when it was found that the 

 gibbous plants were producing thin flat fronds, which were also in flower 

 and floating detached. In both cases the flowers were hermaphrodite, but 

 they had the appearance of being unisexual, on account of the flowers of the 

 gibbous plant protruding the pistil only, while those of the flat fronds evolved 

 only the stamens. After describing the habits of the winter fronds of Lemna 

 polyrhiza and alluding to Lemna minor, the paper concluded with a table 

 of temperatures relating to the germinating, budding, and flowering of 

 these plants. 



A paper was then read "On the fertilization of certain Malayan Orchids," 

 by Mr. H. N. Ridley. 



