Cytology of a new variety of A chly a amei'icana. 147 
with respect to illumination, were indistinguishable from one 
another at all stages of their development. 
Time and opportunity were wanting for detailed investiga- 
tion as to the conditions of germination. After a few weeks, 
too, the necessity which had urged me to examine the 
question disappeared, for excellent material with numerous 
oospores in all stages of germination was furnished by 
cultures which had been allowed to stand in small quantities 
of water in a south window. Such cultures would be 
relatively very well supplied with oxygen, for the continual 
variations in temperature inside the vessel in such positions 
would cause constant fluctuations in the volume of the air 
standing over the water and so aid thorough aeration. Really 
pure cultures, i. e. cultures free from all other organisms than 
the Achlya itself must, I fear, be used to secure perfectly 
satisfactory results as to the conditions of germination, and, 
of course, a much more rigorous method must be adopted 
throughout. 
Induced apogamy. When engaged in following the course 
of development by means of cover-glass moist-chamber 
cultures, the method of cutting off hyphae from larger cultures 
and examining them separately was frequently resorted to. 
It was soon evident that this method offered a means of 
producing apogamous oogonia at will. 
In normal cultures, the oogonia are always provided with 
antheridia. If a hypha bearing oogonia in all stages of 
development be cut off from the rest of the mycelium, 
transferred to a moist chamber and then examined at once, 
it is found that those oogonia provided with a basal wall 
have undergone no change of importance, but that those 
without one have suffered considerably. In the latter case 
the protoplasm of the oogonium under the conditions of the 
operation carried out by me, is in part carried down the stalk 
and a small mass of it even reaches the main hypha. The 
oogonium slowly recovers, most of the protoplasm passes back 
into it, but a little is frequently left behind and undergoes 
what may be called fatty degeneration, being converted to 
