spore- Ciiltu re. i o ; 



points, so that when placed under the microscope there 

 is no necessity to wipe the lower side of the slide. Of 

 course, the length and height of the stand must be propor- 

 tionate to the size of the bell-glass. The best form of bell- 

 glass is that known by gardeners as a propagating glass, 

 which is rather flatter than the ordinary bell-glasses ; the 

 advantage being that the slides are not too far above the 

 surface of the water in the plate, so that the drops of water 

 on them do not evaporate so rapidly. 



Supposing we wish to observe the germination of the 

 secidiospores of Puccinia graniinis, having obtained a per- 

 fectly fresh-gathered leaf of barberry with the yEcidium on 

 it, we proceed as follows. The spores can either be brushed 

 upon the slide with a camel-hair pencil, or what will often 

 be found more convenient, the aecidium can be gently struck 

 upon the dry slide, and a drop of water let fall upon the 

 tiny heap of golden spores that have been displaced. The 

 ripe spores will most of them float on the top of the water 

 and can be readily observed with a quarter-inch objective. 

 The preparation must, of course, not be covered with a 

 cover-glass, and it takes a little patience to examine these 

 uncovered objects, because the front of the object-glass is 

 apt to become bedewed and misty. The only plan is to 

 raise it by the coarse adjustment, wipe it dry, and try again. 



Germination will be well advanced in the course of 

 ten or twelve hours, and the migration of the yellow 

 endochrome along the germ-tube will by that time have 

 taken place. This will be followed by their circumnutatory 

 movements and ultimate branching. Earlier examination 

 of the preparation will show the germ-tubes emerging from 

 the germ-pores. It is useless to attempt to get secidio- 

 spores to germinate unless they are perfectly fresh and 

 perfectly ripe. For instance, the spores dug out from the 

 bottom of an aecidial cup with a needle will not germinate ; 



