iSpO.] NE»V-YORK MICROSCOPICAL SOCIETY. 71 



mass or vegetative system of our fungus chiefly composed. The 

 base of each mycelium is rhyzoid, that is, though not in form, it 

 is in function root-like ; for as rootlets these basal ends pene- 

 trate the solid tissues, and suck or extract the nitrogenous nutri- 

 ment. We may call the outer parts the fronds or branches, 

 as they are the fruit-bearers, the spore capsules, of which our 

 Saprolegnia has two kinds on the same plant. One of these, 

 borne at the end of the hypha, is club-shaped, or with its hollow 

 support looking in the microscope exactly like a miniature bull- 

 rush. This is called a sporangium, and its contained seed-like 

 bodies are known as motile spores, or zoospores, because of cer- 

 tain animal-like movements. 



There is another kind of capsule, usually terminating a short 

 hypha. It is usually flask-shaped, though sometimes globular. 

 This is known as an oogonium, literally, egg-bearer. Its con- 

 tained round bodies are called oospheres, or egg-spheres. They 

 are much larger than the zoospores, and these quasi animal ap- 

 pellations are given them because they have to be fertilized, un- 

 like the seedlets in the sporangium, already noticed as zoospores, 

 or motile spores. In a word these tiny oospheres have a similar 

 necessity to the ovule in a flower, which owes its life force to the 

 pollen from the anther. So to meet this need in our fungus 

 capsule a bud is seen to grow from the pedicle or neck of the 

 oogonium, that is, the capsule containing the spores. This curious 

 organ grows rapidly, and is developed simply in the nick of 

 time; that is, when the oospheres are just on the eve of maturity. 

 At first it is merely a little tube, just long enough for its tip to 

 reach the flask-like capsule above it. Now a change rapidly 

 occurs. A septa or dividing plate grows in the tube, thus mak- 

 ing the upper end a cell. This is filled with protoplasm, which 

 now separated from the protoplasm below the septa, is affected 

 by some special action of organic chemistry, and becomes a lit- 

 tle opaque, and changes into a substance known as gonoplasm. 

 It is now charged with a communicable life essence. At this 

 point of time, from the centre of the disc made by the tip of the 

 cell flattened against the outer wall of the capsule, the tube in a 

 much smaller diameter, thus having a shoulder around it, is 

 lengthened, penetrating the oogonium at a weak spot until the 

 tip of this tube so lengthened reaches the nearest one of the con- 



