342 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



A shallow box, or rather frame, about four inches across, was made 

 from four narrow strips of wood, the bottom being constructed of fine 

 wire gauze, thus forming a sort of small sieve. This was filled with 

 fine earth pressed firmly down, so as to allow as little air as possible 

 to get in between the bottom of the box and the surface upon which 

 the spores were sown. The spores were thus practically underground, 

 and yet could be readily examined by simply lifting the frame. By 

 this process a number of spores of BotrycMum ternatum were made to 

 germinate, and small prothallia were obtained. In this case germi- 

 nation did not occur until nine months after sowing the spores. 



Germinating Fungus-spores and Pollen-grains.*— Mr. T. J. 

 Burrill says that fungus-spores, as a rule, germinate best when sown 

 upon a drop of water in which there is dissolved a small proportion 

 of gum. If the aqueous drop is put on a slide, the spores dusted on 

 the slightly viscid fluid, and the whole kept in a moist chamber for 

 twenty-four hours, at the ordinary temperature of the laboratory, an 

 examination will often be rewarded by an instructive exhibition of 

 germinal tubes. 



The same may be said of pollen-grains, though the addition of a 

 little nectar or sugar to the fluid in this case is useful. 



Cultivation of Pollen-grains.| — In the cultivation of pollen- 

 grains, those of monocotyledons are most responsive, and of all that 

 have been tried, those of Tradescantia are the most serviceable. The 

 pollen-tube begins to develope in a very few minutes, and within an 

 hour becomes many times longer than the grains, and has received 

 the contents. An ordinary moist chamber can be used, constructed 

 of blotting-paper or cardboard, as suggested by Bower and Vines in 

 their ' Practical Botany,' p. 16, and by Goodale in his ' Physiological 

 Botany,' p. 430. The points which experience with this special plant 

 suggests are, according to Prof. J. M. Coulter : — 



1. The culture drop, for a quick response, should be a saturated 

 solution of cane sugar. 



2. I'he pollen-grain should be first placed upon the cover-glass, and 

 then the culture drop added. If the pollen is sown on the culture 

 drop, it will remain too far removed from the objective, and the tubes 

 will mostly grow towards the objective, and so be seen in optical 

 section instead of in profile. 



3. Pollen should be obtained from flowers that have been open for 

 some time. 



" Tradescantia is so common, the moist chambers are so simple, 

 and the response so immediate, that it would seem a pity for any 

 student to fail seeing the extine ruptured, and the intine developing 

 into a pollen-tube." 



Silver treatment of MeduUated Peripheral Nerves.^ — Dr. C. 



Mondino gives detailed instructions as to his modification of Golgi's 

 silver treatment of peripheral nerves. 



This simpler procedure consists in first moistening the nerves in 



X 



Cot. Gazfittc, X. (1885) p. 428. t Ibid., p. 427. 



Arch, per Ic Sci, Med., viii. (1885) p. 45. 



