ZOOLOGY AND BOTANY, .MICROSCOPY, ETC. 



399 



handle the objective is firmly gripped. It adds only I inch to the 

 length of t he body. 



Fig. 65. 



Stiles' " Universal " Microscope Lamp.* — This lamp, made by 

 W. Watson and Sons, as will be seen from the illustration (fig. 66), 

 will be found very serviceable for Microscopical 

 work. 



(6) Miscellaneous. 



Some Hairs upon the Proboscis of the Blow- 

 fly.! — E. M. Nelson recommends a study of the 

 visibility and measurement of the hairs upon the 

 proboscis of the blow-fly as not ouly an excellent 

 practice in minute microscopical work, but as a 

 very desirable introduction to the more difficult 

 examination of the flagella of bacteria. He classifies 

 four varieties of such suitable hairs : — (1) The 

 minute spinous hairs with filamentous ends upon 

 the upper surface of the membrane of the sucker. 

 2. Pliant and soft hairs upon the rostrum. 3. 

 Comparatively giant hairs found both upon the 

 rostrum and upon the maxillary palpi. These are 

 five times thicker than the others are long. One 

 measures 0*063 in. in length and - 002 in. in 

 breadth, while a minute hair measures ' 00044 in. Fig. 66. 



in length and 0*000036 in. in breadth. 4. 

 Tubular blunt-ended hairs 0'0187 in. in length and 0" 00036 in. in 

 breadth ranged round the edge of the suctorial disk. The same supply 

 of air which inflates the tongue also inflates these hairs. The object of 

 this is twofold : first, it renders them stiff enough to afford special 

 protection to the delicate edge of the suctorial disk : and, secondly, 

 when the tongue is relaxed they become flaccid and in no way interfere 

 with the folding up of the organ into the head capsule. 



Navicula Smithii and N. Crabro.J — A. A. C. Eliot Merlin, in 

 examining specimens of Navicula Smithii from the Bay of Naples, has 



* W. Watson and Sons, Ltd., Catalogue, 1909, pp. 122-3. 

 t Journ. Quekett Micr. Club, 1908, pp. 227-8. 

 j Tom. cit., pp. 247-50. 



