PROGRESS OF MICROSCOPICAL SCIENCE. 273 



capillary system. With regard to the pulsation in the wing, Dr. Schcibl 

 has nothing new to add to the observations of Wharton Jones and 

 Leydig. The whole wing is covered, both on the upper and under 

 surface, with extremely fine, sparsely-scattered hairs. These hairs 

 are most numerous on the inner third of the hinder jjart of the wing, 

 and they gradually decrease in number towards the tip. The two 

 wings, taken together, contain from eight thousand to ten thousand 

 of them. They have a general resemblance to those on the body, but 

 are simpler in form. Their length is about 0'2500™'"' in Vesperugo 

 serotinus, the sj)ecies principally made use of in these investigations. 

 Each hair sac has from two to seven sebaceous glands, according to 

 the si)ecies, and one sweat gland opening into its sac. The two outer 

 fibrous layers of the hair sac have no sharj) line of demarcation to 

 separate them from the surrounding connective tissue, but the inner 

 or hyaline coat is highly developed, and, after being constructed 

 beneath the haii- bulb, widens out and encloses the sense-bodies 

 (Tastkorperchen), one of which organs is connected with each hair. 

 The nerves of the wing may be considered to consist of five layers, 

 i.e. there is one occupying the centre of a transverse section of the 

 wing, which gives off on each side of it four others, and these are 

 successively finer and finer as they approach the opposite surfaces. 

 The inner layer and the one immediately on each side of it, consist 

 of nerve fibres with dark borders, the other layers of pale fibres only. 

 The tastkorperchen are connected with the second layer. The fifth 

 layer of finest fibres ends as a network between the innermost layer of 

 cells of the Malpighian layer of the epidermis. The tastkorperchen 

 are shaped like a fir-cone with a roimded apex turned inwards. They 

 lie immediately below the root of the hair ; and their core or central 

 substance is formed of a j)rolongation of the cells forming the two 

 root sheaths of the hair. Their length is 0"0259 and their breadth 

 0'0175""". A nerve containing about six dark-edged fibres is distri- 

 buted to each korperchen. Just before the nerve reaches this organ 

 it splits into two, and three fibres pass to one side of it, three to the 

 other. The fibres are then wound round the body so as to sheathe its 

 cellular core. Dr. Schcibl thinks it probable that the fibres on one 

 side are continuous with those on the oi:>posite side, and that there is 

 thus a bipolar arrangement here. He attributes to the fine network 

 of pale nerve fibres belonging to the fifth layer the appreciation of 

 temjierature, pain, &c. ; to the tastkorperchen the highly-exalted sense 

 of touch. It is carious that both kinds of nerve endings are connected 

 with the Malj)ighian layer of the skin. In conclusion, the author 

 states that he believes he has found similar bodies in peculiarly 

 sensitive places in other mammals, and promises an early account of 

 them. 



The Structure of Chitons is being investigated by Dr. P. P. Car- 

 penter, who, we understand, lately communicated a paper upon the 

 subject to the Boston Natural History Society. The paper will be 

 published soon by the Smithsonian Institution. 



Microscopy at the American Association. — This Association, which 

 will hold its next meeting on the 16th of August next, will continue 



