October, 1922.] 



The Canadian Field-Naturalist 



131 



is spread out over a stick. Froth-like masses of 

 the mold frequently encircle stalks of grass or 

 herbs at a short distance from the ground, the 

 whole having the appearance of the frothy material 

 of the spittle bugs seen on meadow grass in sum- 

 mer. 



15. Physarum compressum Alb .& Schw. 



In the single specimen obtained, the pale gray, 

 subglobose sporangia occur closely crowded to- 

 gether on the substratum, or, in some cases, inter- 

 mixed with plasmodiocarps, and a few are scat- 

 tered singly. There are rounded and angular 

 sparkling lime knots connected by thin hyaline 

 threads. The spores are spiculose and slightly 

 paler on one side. 



16. Physarum globuliferum Pers. 



A large specimen was found on a birch stump. 

 The sporangia were of a mauve colour and each 

 consisted of a small, globular spore case supported 

 by a fine stalk. The size of the patch of sporangia 

 was so extensive in this case that the side of the 

 stump on which it appeared had a mauve colour 



17. Physarum viride Pers. 



The small gathering shows some sporangia with 

 short dark stalks, and some sessile. The peridium 

 is a golden yellow and the capillitium consists of 

 a network of hyaline threads connecting slender, 

 pisiform, orange lime knots. The spores are 

 nearly smooth, 10 microns in diameter. 



This gathering is peculiar in that the sporangia 

 are not like the typical form, that is, they are 

 neither nodding on slender black tapering stalks 

 nor are they symmetrically lenticular or sub- 

 globose 



18. Physarum viride Pers. Var. aurantium 

 Lister. 



The typical globular gray sporangia, nodding on 

 a fine stalk, are present in this specimen. 



19. Physarum polycephalum Schwein (Fig. 2.) 

 This species is characterized by small, grayish 



lobed sporangia supported by a slender stalk. 

 In the specimen obtained there are sporangia 

 which are lenticular in shape as well as the 

 characteristic type. The capillitium is made up 

 of hyaline threads connecting deep yellow lime 

 knots. 



20. Stemonitis herbatica Peck. 



Three specimens were obtained and these illus- 

 trate well its great variability. The sporangia are 

 plume-like networks of brown capillitium sup- 

 ported by fine stalks. One of the specimens has 

 a cluster of ferruginous sporangia 7-8 mm. in 

 height and the spores are almost smooth. An- 

 other has fruits 7-8 mm. high, but these are fuscous 

 in colour and the spores are slightly more violet 

 and are roughened with minute warts. In the 



third collection the fruits are 4-6 mm. high and 

 the spores and capillitium are typical. The capil- 

 litium of each consists of a dense intermediate net- 

 work ending in a small-meshed superficial net. 

 Specimens of this species were the first slime molds 

 observed. They appeared on a stump in the 

 form of small, round, white bodies which might 

 have been mistaken for the eggs of some insect. 

 During the night the white bodies elongated, 

 their colour changed from white to dark brown 

 and they transformed into the beautiful delicate 

 fruiting body typical of this species. 



21. Stemonitis ferruginea E hr enb . 



The representative of this species is rather poor 

 but the sporangia are the typical short brownish 

 ones of the plumose kind. 



22. Stemonitis fusca Roth. 



This gathering is composed of a cluster of dark 

 brown plumose sporangia 4 mm. high. The 

 spores are 8 microns in diameter and their surfaces 

 are reticulate. 



23. Stemonitis splendens Rost. (tentatively). 

 In this specimen the sporangia consist of long 



brown plumose bodies supported by a fine stalk. 



24. Trichia decipiens Macbr. 



The collections of this species have dark brown- 

 ish globular sporangia supported by a fine stalk. 

 The coloration is peculiar, yellow to yellowish- 

 brown being more typical. The elaters are a deep 

 yellow colour and are very similar to some species 

 of Trichia botrytis. 



25. Trichia favoginea Pers. 



In this species the sporangia are characteris- 

 tically bright yellow sessile bodies of elongate oval 

 form. 



26. Trichia persimilis Karst. 



A small mass of densely-crowded, ochre-coloured 

 sporangia make up this collection. The spores are 

 covered with coarse, angular, pitted, wart-like 

 structures which give them an irregular outline. 



27. Trichia varia Pers. 



This specimen was immature when collected and 

 has not the ochre hue of ripe fructifications. The 

 elaters are typical, having two loosely wound 

 spirals, but the spores are thin-walled and irregular 

 in shape. 



28. T ubifer a f err uginosa Gmel. 



A typical flat, brownish sethalium 2.5 x 1 cm. 

 was collected. The surface of the cushion-shaped 

 mass of sporangia presents a honeycomb-like 

 appearance where the tips of the sporangia are 

 broken off. 



29. T ubifer a stipitata Macbr. 



This species is much like the last except that 

 the sporangia are stalked and the cluster thus 

 raised from the substratum. 



