ON SAPKOLEGNIiE. 283 



accuracy of these observations ; the amoeboid motion continued 

 for some time, then slowly, ceased, and at 10 minutes past 4, 

 the two perfectly spherical oospheres lay obliquely in the 

 oogonium, mutually in contact, as shown in fig. 14. The 

 oospheres in this condition are apparently ready for "fertili- 

 zation," and the following phenomena occur. 



One or more of the antheridial tubes, coiled closely about 

 the oogonium (figs. 10, 11, &c.), while the above described 

 processes have been going on, begins to send a tubular process 

 through the oogonium wall, at or about the time when the 

 oospheres are smooth and rounded off; the tubular process 

 thus sent into the cavity of the oogonium (fig. 12) has been 

 termed the " fertilising-tube." It is a direct prolongation of 

 the *' antheridial branch," and contains finely granular proto- 

 plasm; it grows for some time in the cavity of the oogonium, 

 coming in contact with the oospheres — even running on their 

 surfaces. I have never seen it enter an oosphere, nor have I 

 seen it open at the end or emptied of contents. Whether any- 

 thing passes from it to the oospheres cannot be decided ; but 

 De Bai-y gives such strong reasons for doubting that any fer- 

 tilising process whatever occurs, and supports his conclusions 

 by so many examples and so much observation that it would 

 be presumptuous to attempt to decide the question without de- 

 voting at least equal energies and time to the task. So far as 

 my observations go, they decidedly fail to supply evidence 

 for the view that anything is emptied from the tube into the 

 oogonium or oosphere. Before offering any further remarks 

 on this subject, it will be convenient to describe the remaining 

 observations made on other species. 



Achlya apiculata is the name by which Professor De Bary 

 designates a species not yet (I believe) described ; my observa- 

 tions on this form are not yet sufficient to enable me to do more 

 than depict the formation of the zoospores. I have never seen 

 the Oogonia or Antheridia. 



cording to De Bary, iu Saprolegnia ferax ; he thinks it due to the throwing 

 off of water. May not the bodies, however, be of tlie nature of the "Polar 

 cells " thrown olF from the animal ovum preparing for fertilization? 



