12B THE JOURNAL OF BOTANY 



P. DiDEEMOiDEs (Acli.) Eost. Large growths were found afc 

 Ibadan in August 1915 developing from opaque white plasmodium 

 on rough bark of trees and on smooth bark of hanes. They 

 exhibit two strikingly different forms of growth. One is the form 

 frequently met with in Europe, having loosely clustered sessile 

 subglobose sporangia, grey or dirty white in colour, and often 

 connected by strands of membranous liypothallus ; the other 

 form presents a very unusual appearance from the sporangia 

 being flattened and closely united to form well-defined white 

 plate-like masses 5 to 20 mm. across. Some of these show under 

 a low magnification curious markings in the form of concentric 

 circles. Both the scattered and united sporangia may occur near 

 together on one strip of bark, and evidently all belong to one 

 species. The spores and capillitium are alike in all. 



P. CEATEEiFOEME Potch. Found in some abundance at Ibadan 

 on the stalks of a pigeon-pea {Gajmiiis sp.). Mr. Farquharson 

 sends interesting observations on the development of this species. 

 He describes how the plasmodium appeared after the ground 

 below the plant had been moistened by copious drippings or 

 " cuckoo-spit " emitted by a large frog-hopper (Ptyelus grossus 

 Fabr.) ; the insects puncture and suck moisture from the stalk of 

 the pea, and exude it again in a shower of drops. Thus even in 

 dry weather the ground beneath became sufficiently moist for the 

 perfect development of the Physarum. The sporangia sent are 

 globose and often umbilicate above ; the short dark stalks and the 

 lower part of the sporangium-wall contain deposits of small green 

 alga-cells ; the columellee vary in shape and size, and are either 

 hemispherical, clavate, or slender and cylindrical and reaching to 

 the apex of the sporangium ; they enclose lime-granules and alga- 

 cells ; the spores are pale violet-grey, 7 to 10 /z diam. 



P. COMPEESSUM Alb. & Schw. Frequent at Ibadan on the 

 decaying male inflorescence of oil palms and on old cocoa pods. 

 The compressed sporangia are confluent in scattered groups of 

 from two to twenty ; the lime-knots are numerous and rounded ; 

 the dark grey clustered stalks enclose abundant refuse matter. 



P. EENiFOEME (Mass.) Listcr. Fairly common at Ibadan, 

 especially on the cut ends of oil palms. Very similar to the 

 preceding species, but the sporangia are more lobed and undulate ; 

 the stalks are long, buff, and, in these developments, free from 

 refuse matter, and the angular lime-knots are more or less com- 

 bined to form a pseudo-columella. 



P. ciNEREUM Pers. Found once at Ibadan on decaying palm 

 fibres on swampy ground, also on living herbaceous plants. 



P. GYROSUM Post. Ibadan. Large developments of cream - 

 white Plasmodium were found which matured on the stems of 

 ground-nut (Arachis), grass, etc. A few sporangia are free and 

 mounted on slender dull-red membranous stalks, but most are 

 united to form extensive net-like plasmodiocarps, about 1 mm. 

 high, and seated on a dull red hypothallus. 



P. digitatum G. Lister & Farquharson, n. sp. (PI. 541, lig. 1). 

 Plasmodium greyish-yellow. Sporangia cylindrical, ascending, 



