88 



creature a greater mechanical power of adhesion in certain cases. A 

 drawing illustrating the size and position of the plates was also exhi- 

 bited. 



Mr. Queketl then directed the attention of the Society to an obser- 

 vation of a somewhat similar nature to that of Mr. Spencer, which he 

 had made about ten years since, in the structure of the skin of a vivi- 

 parous blenny iZoarcus viviparus). In the description of the skin of 

 this fish, Mr. Yarrell states that " the surface of the body appears, 

 under a lens, to be studded with circular depressions ;" it was found, 

 however, that these circular depressions, which are always of a white 

 colour, were due to the presence of small, round scales, about one- 

 twelfth of an inch in diameter, each having a minute black spot; these 

 are situated deep in the cuticle, like those of the eel, and in some 

 situations occurred at certain tolerably regular distances. 



Mr. Quekett afterwards spoke of what appeared to him a new fact 

 in vegetable physiology, viz., the unrolling (in a spiral manner) of the 

 membranous wall of an elongated cell. The specimen from which the 

 hair or hairs were taken, was the fruit of Cycas revoluta, from China. 

 Upon detaching some of these hairs, which are situated on two oppo- 

 site parts of the fruit, and examining them with a power of 250 dia- 

 meters, two varieties were distinctly visible, viz., perfect hairs, having 

 both extremities more or less pointed, and others, in which the extre- 

 mity attaching them to the seed was abruptly broken off: when these 

 last were carefully examined, the broken ends were in most cases 

 found unrolled in a spiral direction, the spiral being in the form of a 

 band, the breadth of which gradually increases from below upwards. 

 In these hairs there was no trace whatever of a spiral fibre, the mem- 

 brane forming the wall being quite transparent and free from structure. 

 Now, in most of the works on botany no mention is made of the man- 

 ner in which vegetable membrane is capable of being torn. Dr. Lind- 

 ley, however, in the last edition of his ' Introduction,' states that it 

 generally tears irregularly, but that in Bromelia nudicaulis the torn 

 edges are curiously toothed; but no instance is given in which the 

 fractured portion is always in a spiral form. It was on this account 

 the subject was brought before the notice of the Society. 



Mr. Quekett then brought forward a curious instance of malforma- 

 tion in the spicula, both of the body and of the gemmules, of Spon- 

 gilla fluviatilis. The specimen in which the spicula occurred, was 

 foimd by Mr. Spencer, in the neighbourhood of Blackheath, and the 

 drawings were made by Mr. Leonard, from two objects, one belonging 

 to the Society, the other in the author's possession, both of which were 



