Fungi. 205 



are entirely impalpable and invisible singly, the largest of them requir- 

 ing to be magnified 360 diameters under the microscope before they be- 

 come visible. Their number is inconceivably great, and whenever any 

 spot furnishes the proper conditions of temperature, moisture and or- 

 ganic matter, whose chemical bonds are not too strong or have been 

 loosened by decay, some of them are sure to find it speedily. Certain 

 species are so abundant in the air that it is almost impossible to keep 

 them out of even closed vessels, especial^ such as the common moulds 

 aspergillus and penicillium. 



Gardeners of ten raise agarics by simply making a bed of mixed horse 

 and cow ordure, in which the spores are expected to find lodgment and 

 germinate. It may be assumed, in some cases, that the spores have 

 been eaten and have passed through the stomach unhurt and not only 

 so, but it is even supposed that the germinating powers of the spores 

 are only brought out better by the process. 



There is variety both in the mode of producing the spore or seed and 

 in the manner of its development into the plant. On the supposition 

 that the fungi are degenerate plants that have lost the chlorophyl or- 

 gans, we might expect to find some trace of their ancient relationships 

 in their mode of development. In some cases observers have been able 

 to do this. 



The development of the Conio-Mycetes is proved to be an alternate 

 generation. That is, the spore does not grow at once into the full fun- 

 gus conio-mycetes, but produces what is called a pro-mycelium. This is 

 a long tube of thin membrane, and into it the protoplasm of the spore 

 enters, doubtless dilated by the absorption of water. The tube takes a. 

 curved shape and is rounded club-like at the end. On the end and 

 sides of this tube, or promycelium, four spicules, or small projections, 

 are formed, and on the ends of these are developed a second set of 

 spores called sporules, and these then germinate and proceed to develop 

 the true mycelium for the full grown plants. The first set of spores, 

 those that develop the promycelium of the coniomycetes, are called 

 pseudospores to distinguish them from the last ones. This mode of de- 

 velopment by alternate spores is quite common among these fungi. 

 Now we will compare this with the development of the Bracken Fern. 

 This is classed as a cryptogamic plant. When the Fern is mature it de- 

 velops sporangia on the underside of the leaf stems. In these sporan- 

 gia the spores are developed by a fissive asexual process. When the 

 spores are set free they germinate and sprout into a small cellular plant 

 which is called a protJiallus ( first twig ). The protoplasm of this pro- 

 thallus becomes differentiated into male and female. An antheridium 

 containing active antherozooids ( or male cells ) being formed above and 

 an embryo cell below. The antherozooids move down a canal by means 



