ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



525 



days. The first visible growth is on the surface of the medium, but in 

 about a fortnight the substratum may be invaded to the depth of a 

 centimetre. As the bodies are not microbic or crystalline in nature the 

 author is disposed to regard them as colloid substances, and terms them 

 radiobes in view of their resemblance to microbes and of their nature and 

 origin. 



(2) Preparing Objects. 



Blood Spreader.* — This instrument, devised by M. J. Rosenau, is 

 made by welding two pieces of solid glass rod together (figs. 116, 117). 



Fig. 116. 



The short arm should be true so as to lie flat when applied to the slide, 

 and should be several millimetres shorter than the width of the slide. 

 A drop of blood is taken from the ear or finger-tip and placed upon one 



Fig. 117. 



end of the slide in the usual manner. The spreader is then applied to 

 the drop, and if the glass be clean the blood will at once be drawn by 

 capillary attraction across its whole length ; it is then stroked gently 

 along the slide. 



Preparing and Staining Eye of Honey Beef.— For demonstrating 



the structure and development of the compound eye of the honey bee, 

 E. F. Phillips proceeded as follows. Larvae and pupa? were fixed in 



* Yellow Fever Inst., Bull. 14 (Washington, 1905) pp. 52-3 (2 figs.). 

 t Proc. Acad. Nat. Sci. Philadelphia, lvii. (1005) \\ 12".. 



