276 ON ABNOEMAL HORNS OF CERTUS SIKA. [Apr. 2, 



would justify the placing of the horny spines in any other category 

 than as modified tracts of epidermis. The whole structure is an 

 exaggeration of the pads of thickened epidermis upon the soles of 

 the foot, and is in all probability comparable to such callosities as 

 those found in the Equidae. In any case I claim to have disposed 

 of any theory that could account for these horny spines as the 

 hardened secretion of a gland. They are plainly of a corn- or 

 wart-like texture, though possibly to be looked upon as a patho- 

 logical condition which has persisted and become normal. 



A final point to which I would direct attention in this communi- 

 cation is the interesting correspondence shown between hand and 

 foot. A structure peculiar to the hand of one Lemur is now known 

 to characterize t\\e foot of another species. There are among the 

 Mammalia but few details of structure in which the hind limb does 

 not, as it were, copy the fore limb. This correspondence is shown 

 among the Lemurs in another curious point to which attention 

 has of course been directed, since the facts are well enough known. 

 It is not unusual in that group for the second digit in both manus 

 and pes to be peculiar in some respect. This digit in the foot has 

 a claw instead of a nail, while in the hand it is sometimes aborted 

 altogether. The structure, however, with v\hich I deal in the 

 present paper is a positive and detailed point of likeness between 

 hand and foot. 



April 2, 1901. 

 Dr. A. GiJNTHEU, F.E.S., Vice-President, in the Chair. 



Prof. Bell exhibited two specimens of an Echinoderm, Astro- 

 phyton davatum, the many-branched arms of which were closely 

 entertwined, while the bursal slits (by which the genital products 

 are evacuated) were turgid and widely open. 



Recalling the observations of Prof. Ludwig on Asterina and of 

 Dr, Jickeli on Antedon, Prof. Bell suggested ttiat we had here a 

 third example of sexual congress among Echinoderms. He further 

 stated that he had called the attention of his valued correspondent, 

 Mr. F. W. Townsend of Karachi, from whom the Trustees of the 

 British Museum had received the specimens, to the difference in 

 coloration between the two specimens, and had asked him to use 

 his opportunities for discovering if the difference was constant 

 and sexual. Since he had come into the room, Mr. Byrne had 

 suggested to him that the entanglement of the arms might aid in 

 the fertilization of the ova. 



Mr. E. E. Holdiiog exhibited and made remarks upon the horns 

 of a Japanese Deer {Gervus sika), indicating arrest in the develop- 

 ment of the left horn, apparently due to a cerebral tumoiir and 

 adhesions in the right hemisphere of the cerebrum. A dissection 



