132 



BOTANY. 



as a man's hand. This mass of protoplasm, known as the Plasmo- 

 dium, is often yellow or orange-red in color, and is never green. It 

 possesses to an extraordinary degree the power of moving itself from 

 place to place. Slime-moulds obtain their food by absorbing solu- 

 tions of decaying matter, and even engulf solid substances in the 

 same manner as the Amoeba. 



C. Spore-formation. — When they have become full grown, they lose 

 a good deal of their moisture, and the protoplasm then separates it- 

 self into a great number of minute rounded balls, each of which 

 forms a cell-wall around itself. These little balls (spores) are thus 

 nothing but bits of protoplasm securely covered. They may now be 

 blown hither and thither without harm, and when at last they fall 

 into a moist warm place they imbibe water, burst their coats, and 

 are free naked masses of protoplasm again, thus completing the 

 round of life (Fig. 64). 



D. In its spore-bearing stage each Slime-mould is covered with a 

 membrane (^peridium), while internally it forms (1) spores, and 



(2) sometimes a filamentous 

 framework (capillitium). In 

 this stage its form is either (1) 

 irregular in shape, resembling 

 a dried Plasmodium (then 

 called a plasmodiocarp), or it is 

 (2) a sporangium of uniform 

 and regular shape (Fig. 65, it, 

 b, c, d). 



B. About 400 species of 

 Slime-moulds have been recog- 

 nized. They have been classi- 



Fig. 65.— Several forms of the spore- fied almost entirely upon char- 

 bearmg stage of Sbme-moulda. a, Bad- , . _ , 



hamla, X 20 ; 6, Reticularia, X hi; c, acters derived from their spore- 

 Physarum, x 20; d, Stemonitis, natural bearing stage. Many species 



occur in all parts of the United 

 States, and may be readily found on the bark of trees, decaying logs, 

 stumps, decaying mosses, etc., and on the bark- covered ground in 

 tanyards. A fine large one — Fuligo varians — is especially common in 

 tanyards, on manure-piles, and in and upon decaying planks of side- 

 walks. 



Systematic Literature.— Ma.ssee, Monograph of the Myxogastres. 

 Lister, Monograph of the Mycetozoa. Saccardo, Sylloge Fungorum 

 7'. 



