. Minnesota plant diseases. Plant diseases. io6 Minnesota Plant Diseases. ever, all aquatic in habit and thrive in stagnant pools where decaying animal and plant materials are particularly abundant. They are typically half-saprophytes, passing most of their life feeding on dead material in the water, but living parasitically on fish or other animals, as occasion presents itself. As wa- ter plants they utilize the swimming spores and these are usual- ly formed in enormous numbers in spore cases of various shapes. The swimming spores are of the same general struc- ture as those of the lower alga
. Minnesota plant diseases. Plant diseases. io6 Minnesota Plant Diseases. ever, all aquatic in habit and thrive in stagnant pools where decaying animal and plant materials are particularly abundant. They are typically half-saprophytes, passing most of their life feeding on dead material in the water, but living parasitically on fish or other animals, as occasion presents itself. As wa- ter plants they utilize the swimming spores and these are usual- ly formed in enormous numbers in spore cases of various shapes. The swimming spores are of the same general struc- ture as those of the lower algal fungi, though in a few cases they seem to be unable to get out of their spore cases and they then grow out into threads while still inside of the case and never develop whips. All the fish and water molds develop breeding organs of two kinds, male and female. The female are usually ical cases, contain a number of and the male organ is an elongated thread which is sometimes branched and usually arises from the same thread which pro- duces the swollen egg case. Now the male thread pene- trates the egg case and can be seen making its way between and around the eggs, but a remarkable feature lies in the fact that they never as far as has yet been observed breed with the egg cells. The latter nevertheless. organs spher- which small eggs, Fig. 42.—Water and fish molds. 1. A fungus thread with an unopened spore-case. 2. An opened spore-case with fhe escaping swimming spores. 3. An egg-case with the male threads penetrating it. The spherical bodies in the egg-case become the resting egg-spores. Highly magnified. 1 and 2, after Thuret; 3, after Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Freeman, Edward Monroe, 1875-. Saint Paul, Minn.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectplantdi, bookyear1905
