38 

 PARASITIC FUNGI. 



By Adolph Lehmann, B. S. A. 



(Read at Microscopical Soiree, No. 2, 2§tJi February, i8g2.) 



One of the many branches of science which is ahiiost exclusively 

 dependent on the microscope for its development, is Mycology or the 

 study of that group of minute plants known as lungi. 



This group is an exceedingly large one and, as might be expected, 

 some of its members vary considerably in size and appearance; even 

 more so than some of our forest trees differ from the herbaceous plants 

 growing underneath them. A few like the mushrooms and toadstools 

 are comparatively large; but the numbji of these compared with those 

 invisible to the naked eye is so small that if the average size of the fungi 

 could be ascertained this would not be materially increased by the 

 former. Therefore, speaking of the group, we call it one of microscopic 

 plants; or plants of which even the outline cannot be seen without a 

 microscope. 



In addition to great differences in size, very viried forms of structure 

 and reproduction are found in this group ; but one of the character- 

 istics the fungi have in c )mmon is that they do not possess the peculiar 

 green colouring matter, called chlorophyll, by which other plants are 

 enabled to transform water and the carbonic acid of the atmosphere 

 into starch or some closely allied compounds. Not being able to do 

 this they must absorb them from other plants or animals or some of their 

 products. They are, therefore either parasitic or sapro[)hytic ; the 

 former if they draw their nutriment from living tissues, the latter if 

 from their remains. 



Nearly all the fungi have numerous slender filaments ramifying 

 through the material on which they live. Generally this is the only por- 

 tion of the plant existing in its early stage. It grows very rapidly and 

 constitutes what is known as mycelium. From it, branches are sent out 

 which, either directly or indirectly, produce minute reproductive cells 

 called spores. Like the seeds of the higher plants, these serve the 

 double purpose of multiplying and perpetuating the species. Many 

 fungi produce two kindsof spores the one for quickly spreading its growth, 

 the other, a resting spore, able to withstand extremes of climate, for 

 tiding over periods unfavourable to the growth of the parent. Most 



