ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



237 



Reiser's Bacterial Filter for Small Quantities of Fluid.*— To 



the bou.trie F (fig. -1:5) is closely adapted a glass cylinder ending above 

 as a tuioe A, connected with a piece of rubber tubing. Between the 

 filter and the glass cyhnder is merely a capillary space so that when the 

 apparatus is set working the fluid can be filtered to the last drop. To 

 the bottom of the cylinder is fitted 

 a brush K, which cleans the filter 

 from bacterial slime. 



/""^ 



Studying: Fecundation in Ser- 

 pula.+ — A. Soulier points out that 

 artificial fecundation in Serpula is 

 facile and constant ; it is easily 

 obtainable throughout the year. It 

 is quite suflBcient to place the male 

 and female genital products on a 

 watch glass ; fecundation takes place 

 and development follows its normal 

 course. 



The ovules are picked out at 

 various stages of evolution (5, 10, 

 If) minutes, and so on) and then 

 placed in a fixative. 



A temperature not exceeding 15° 

 is advised for observing the normal 

 fecundation course. If from 12"- 

 15°, fecundation takes place in 

 from :->0-4:5 minutes after the 

 sexual elements have been mixed 

 together. Segmentation follows 

 within 5 hours after. By the second 

 and third day the larval organs 

 are complete. If the temperature 

 be 8°, fecundation takes 8 hours, 

 and other stages in proportion. 



Numerous fixatives were used, the least unsuccessful ones being the 

 fluids of Flemming, Fol, and Cori. The successful ones were Gilson's, 

 Roule's, and Ripart and Petit's. All these last three gave excellent 

 results provided they were diluted to 1 part fixative to ?> of sea water. 



The sections were stained with picrocarmin, safranin, etc., according 

 to the procedures ordinarily used by histologists. Double staining with 

 ha^matoxylin and eosin gave excellent results. 



Simple Steam Steriliser and Hot-water Filter. f — This apparatus 

 (fig. 4-(;) has been devised by A. Frazer to meet the requirements of 

 those who wish to conduct the operations of sterilising and filtering in 

 a single vessel of small size and moderate cost. The apparatus is of the 



Fig. 45, 



ordinary shape, while the 



height 



of the cyhnder is 16 in. and the 



* Chem. Zeit., xxx. (1906) p. 686. See also Deutsch. Mechaniken-Zeit., 1906, 

 p. 206_^ t Arch. Zool. Exper., v. (1£C6) jjp. 403-89 (1 pi. and ei f gs, in text). 



X Proc. Scot. Micr. Soc, iv. (1906) pp. 68-9 (1 fig.). 



