


ee ee a 
Igor | GERMINATION OF SPORES 4I 
influence, as likewise small quantities of poisonous substances. 
The further interesting fact was disclosed that the effect of 
light is not one of photosynthesis. Equisetum spores, moreover 
according to Sadebeck,? germinate well either in light or in 
darkness. 
Notwithstanding the excellent culture methods for the fungi, 
a study of germination in relation to the stimuli involved has 
been largely a matter of incidental consideration. A study of 
growth phenomena, thermal limitations of growth, toxic effect, 
etc., have furnished some data relative to the stimulus of partic- 
ular substances. It seems, however, that no summation of the 
results has been made since the work of DeBary.” 
METHODS. 
The most convenient method of observing spore germination 
is undoubtedly the hanging drop-culture. The principal points 
to be considered in properly handling the drop-culture, or Van 
Tieghem cell, where nutrient media are employed, have been 
recently set forth clearly by Clark. These notes bear repeti- 
tion to a certain extent. The employment of large rings is 
desirable, and they should be cemented to the glass slips by a 
mixture of refined beeswax and pure vaseline. The cover 
should be cemented to the ring with vaseline. The same char- 
acter of liquid should be used at the bottom of the cell as 
employed in the drop. 
While the form of cell culture above described is highly 
accurate for culturable forms in nutrient media, it is by no means 
@ccurate in all other cases. When a careful study is to be made 
of particular stimulants in water, or in a medium not ordinarily 
Causing abundant germination, and the like, recourse should be 
had to a different method. My experience has been that the 
“ saanaig Re Ueber die Entwickelungsgeschichte d. Le U, S. W der 
e. Sitzungsber. d. Versammlung deutscher Naturforscher u. Aerzte zur 
amburg, 1876. : 
* DeBary, A.: Morphologie und Biologie der Pilze, 376-377. 1884. 
™ CLARK, J. F.: Dissociation and toxic effect. Journal of Physical Chemistry 3: 
263-316. 1899, 
