I 



3072 Microscopical Society. 



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, how 

 ever, 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 si- 

 tuated on two opposite parts of the fruit, and examining them with a power of 250 

 diameters, two varieties were distinctly visible, viz., perfect hairs, having both extre- 

 mities more or less pointed, and others, in which the extremity 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 membrane forming the 

 wall being quite transparent and free from structure. Now, in most of the works on 

 botany, no mention is made of the manner in which vegetable membrane is capable of 

 being torn. Dr. Lindley, 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 malformation in the 

 spicula, both of the body and of the gemmules, of Spongilla fluviatilis. The speci- 

 men in which the spicula occurred, was found 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 

 prepared by Mr. Spencer, from the sponge in question. Some of the long spicula 

 from the body, which were of the form termed by Mr. Bowerbank, ' biarcuate,' were 

 curiously altered, some having portions of the shaft dilated into round nobs at dif- 

 ferent distances, whereby a moniliform appearance was produced, others having por- 

 tions of spicula projecting from their sides, whilst in some few instances, a series of 

 half spicula were developed from the central portion of the shaft in the form of 

 whorl. Amongst the spicula of the gemmules some few were found in their normal, 

 viz., birotulate state ; but in the majority of instances, either one or both extremities 

 were strangely malformed. Sketches of the principal varieties, made by means of the 

 camera lucida, were sent round for inspection. — J. W. 



