74 



THE POPULAR SCIENCE MONTHLY. 



and, when I held a magnifying glass over them, it was like look- 

 ing down on a fairy forest of brown-stemmed, "branching trees 

 covered with a luxuriant, silvery foliage. In this miniature tree 

 I recognized a mold called Polyactis (many-branched), a fungus 

 that is sure to show itself, sooner or later, on decaying vegetables. 

 To remove one of the little trees and place it under the micro- 

 scope required as much patient care as I could muster ; for not 

 only does the Polyactis take a firm hold of the leaf-base with its 

 spreading, root-like hyplicv, but at the least jar it sheds its foliage, 

 branches and all, and nothing remains but an uninteresting, point- 

 ed stem. Yet, if we could continuously watch this stem for a day 



or so, it would prove anything but 

 uninteresting. Almost at once the 

 protoplasm stored within it begins 

 to form other branches as luxu- 

 riant as those that fell. When 

 each is furnished with a due 

 amount, a partition cuts it off 

 from the main supply. Hence- 

 forth it rests merely upon the pa- 

 rent stem. It sends out branches 

 on its own account, and gradually 

 gives over its protoplasm to them. 

 These branches fork and fork 

 again, until at last the proto- 

 plasm is all concentrated in the 

 ends of tiny branchlets, which 

 swell and sprout all over with 

 little points or sterigmata. Each 

 little point contracts and then 

 swells at the end to form an oval, 

 bladder-like body. It is these oval 

 bodies that give the look of foliage to the Polyactis, and as soon 

 as they have received the whole nourishment of the branchlets 

 they cut themselves off from their sterigmata and hang together 

 in a grape-like cluster. These are the conidia that it has been the 

 business of the whole plant to produce, and, in order that more 

 may be borne by the same stem, they must speedily fall and carry 

 the empty branches with them. 



The third crop appeared where I least expected to see it on 

 the heads of my Polyactis. First of all, fine, silvery lines ran from 

 one Polyactis tree to another, looking, through the magnifying 

 glass, like part of some complicated system of telegraph wires. 

 In a day or two they formed a perfect network, on which pink 

 dots began to appear. The dots increased in number, and soon 

 the Polyactis was completely covered with a pinkish film. The 



Fio. 2. Polyactis cinebea. 



