• Communications. 263 



growth, cells or globular bodies resembling the regular cells of 

 the plant are observed. These sometimes lie right in the line of 

 the mycelium, but at others are attached to it by a short stem. 

 (See Fig. 5.) At first they are transparent, and are filled with a 

 fluid or protoplasm of a granular character. These cells are 

 called oogonia, and in their mission represent the ovules of the 

 flowers in plants of higher order. Near these oogonia there are 

 usually seen similar bodies or cells, borne on the extremities of 

 branches growing out of the smaller mycelia. These cells are 

 more obtuse in form, and much smaller than the oogonia, and are 

 also filled with a finely granulated fluid. These represent the 

 male organs of the flower, and are called antheridia. In their de- 

 velopment, these cells gradually draw nearer together, and at 

 length are brought into close contact. When they have reached 

 full size, the granules which had heretofore floated independently 

 about in the formative fluid in the oogonium, gather at the center 

 and assume a spherical form, which is termed a gonosphere. " This 

 gonosphere having been formed, a straight tube shoots out from 

 the antheridium, which perforates the wall of the oogonium, 

 passes through the fluid which surrounds the gonosphere, elon- 

 gating itself until it touches that body. From this period a 

 membrane begins to be formed about the gonosphere, which 

 thenceforth maintains a regular spheroidal form. It may be ob- 

 served that the extremity of the tube which proceeds from the 

 antheridium does not open, and the fecundation, if such it be, 

 seems to be produced solely by contact. After this contact of 

 the two bodies, the gonosphere is called an oospore. The mem- 

 brane which at first invests this organ is very thin, but by depos- 

 its from the surrounding fluid it attains to a greater thickness, 

 and becomes at length of a yellowish brown color, having its 

 surface studded with prominent obtuse warts. One of these 

 warts, larger than rest, incloses the fecundating tube." 



The production of these resting spores maybe carried on in all 

 parts of the plant, but they are found most abundantly where the 

 tissues are reduced to a soft pulpy mass. When the fall is a dry 

 one, they often remain through the winter months in the tissues of 

 the leaf, stalk or tuber, but they are generally washed out of 



