940 RECORD OF CURRENT RESEARCHES RELATING TO 



supplying it with rain, pond, and spring water, in turn, but always 

 with the result that after a short time it disappeared. In October, 



1878, however, he put a small quantity, probably not more than one 

 hundred individuals, in a four-ounce bottle, having a mouth three- 

 quarters of an inch in diameter, and set this on a shelf at the side of 

 an outhouse, which had no gutter, so that the rain in running off the 

 roof would drip into the bottle ; here it has remained until November 



1879, and instead of the few original specimens, they are now 

 abundant. The water has never been changed or replenished, only 

 that which dripped naturally from the roof into the bottle having 

 been added to the original stock, and during the abundant rains of 

 this year the bottle often overflowed. Several times a portion of the 

 water containing the Volvox has been placed in the jars and dishes 

 standing in various parts of the garden, but these always died in a 

 short time, whilst those left in the small bottle, treated as above, 

 remained in perfect health and multiplied. The position in which 

 the bottle was placed faced the north, so that it only got the sun in 

 the early morning of the summer months. During the severe weather 

 of last winter, the water was several times frozen into a solid mass of 

 ice, but apparently without injuring the Volvox. 



MICEOSCOPY, &o. 



Soap as an Embedding Substance.* — Some of the chief objections 

 to the methods of embedding in oleaginous or waxy mixtures seem to 

 be successfully met by the use of the preparation recommended by 

 Dr. Kadyi, and its capability of modification according to the different 

 substances to be embedded is strongly in its favour. 



The best materials and proportions are as follows : — 28 grammes 

 of shavings of stearate of soda soap (that sold as '' weisse Wachs- 

 kernseife" abroad is best), lOO^rcub. cent, of 96 per cent, alcohol, 

 and, generally, 5 to 10 cub. cent, distilled water. The two first 

 ingredients are warmed together on the water bath and to the liquid 

 mass the water is added gradually, until it coagulates quickly into a 

 transparent mass when dropped into a watch-glass. The mixture 

 should be kej)t in a stoppered bottle. 



For use, it is melted or boiled and the object at once plunged in. 

 When cool, sections of it are taken with a razor wetted with strong 

 alcohol, this liquid being also used, warm or cold, to dissolve out the 

 soap fx'om the sections. 



Thus used, the material is adapted best to delicate objects; it 

 possesses transparency and elasticity, and penetrates pores and cavities 

 eflectually. 



A tougher preparation, suited to harder, such as chitinous, tissues, 

 is obtained by increasing the proportion of soap to an almost equal 

 amount by weight with that of the alcohol. 



Logwood Staining Solution.! — Dr. E. A. Cook points out that 

 in most text-books this is stated to be good in results but uncertain 

 in action ; and from the numbers of formulte given for its preparation, 



* ' Zool. Anzciger,' ii. (1879) p. 47(3. 



t ' Jouru. Auat. ami Phys.' (Humphry), xiv. (1879) p. 140. 



