OBSERVATIONS ON OAPILLITIA OF MYCETOZOA. 



By a. E. Hilton. 



{Read November I2th, 1918.) 



The resemblances of Mycetozoa to the Fungi with which they 

 were formerly grouped are most apparent in the structure of 

 their sporangia. In the amoeboid, plasmodium stage, which 

 precedes spore-formation, all likeness to Fungi is absent, that- 

 phase being the distinctive peculiarity of Mycetozoa ; but when- 

 the creeping plasmodia come to rest, and form up into fixed 

 receptacles containing spores, their features so far correspond 

 with those of certain Fungi that a terminology, including the 

 words "sporangium," " capillitium " and "columella," is 

 applicable to either. In both of these groups the term " capil- 

 litium " denotes thread-like tubes or fibres associated with 

 masses of spores within a sporangium. The origin of such 

 filaments, in the case of the Fungi, is partially elucidated by 

 processes occuring in Lycoperdacbae, concerning which it is 

 stated by de Bary that in the spara-bearing receptacles there 

 are numerous delicate tubes or hyphae which ultimately become 

 dry by evaporation of water, and so form " a woolly mass of 

 loose texture, the capillitium, the interspaces of which are 

 filled with large quantities of a dry powder, the ripe spores." * 

 As regards the capillitia of Mycetozoa, it is evident that the 

 formative processes have many modifications. For so smalJ 

 a group the variety is surprising. The capillitial threads may 

 be rigid or flexible — they may lie freely among the spores, like 

 elaters, or be attached at either end to the walls of the sporangiuns 



* Comp. Morph. and Biol. Fungi, Mycetozoa and Bacteria, by A. de» 

 Bary, 1887, p. 310. 



