CH. VIII.— MORPHOLOGY AND COURSE OF DEVELOPMENT. — MYXOMYCETES. 437 



septate tube separating into countless branches, which form a net-work by their 

 anastomoses. The thick homogeneous wall has the same colour as the sporangium- 

 membrane, and its outer surface is usually furnished with projections which take the 

 form either of small spikes or warts, or of annular or semi-annular transverse ridges 

 according to the species. In Arcyria punicea and A. cinerea the capillitium is 

 anchored by the blind ends of branches of the net-work which are grown to the lower 

 part of the wall of the sporangium. In most species (A. incarnata, A. nutans) it is 

 nowhere in connection with the wall, but is fastened loosely by a few branches from 

 the tubes, which descend into the stalk and are squeezed in between the cells which fill 

 it up and which will be described presently. So long as the capillitium is inclosed in 

 the sporangium its branches are all bent in every direction and folded up, and the meshes 

 with their four, five or more sides are narrow and irregular. When the sporangium 



Fig. 192. a, b Arcyria incarnata, P. in outline, a a ripe spor- 

 angium closed, b the same open with the expanded net-work of 

 the capillitium. c, d Arcyria Serpula, Wigd. (A. anomala, De 

 Bary.) c portion of a capilitium. d a spore, a and* magn. 20, 

 c and d 390 times. 



Fig. 193. a, b Trickia fallax. Fr. a half of a 

 capillitium-tube. b superficial view of a spore. 

 c, d Trichia chrysosperma, DC. De By. c ex- 

 tremity of a capillitium-tube. d spore. Magn. 

 390 times. 



opens on reaching maturity, the branches straighten themselves in most species 

 (A. cinerea is an exception), the meshes become broader and the circumference of 

 the net-work many times larger (Fig. 192 a, b), and the structure never returns in any 

 degree to its original form. 



The capillitium-tubes of Trichia and Hemiarcyria which have frequently been 

 described are united in the latter genus (H. rubiformis, H. clavata, &c.) into a net-work 

 with branches which at the same time have free extremities. In Trichia (Fig. 193) 

 they are quite free, and either simple or furnished with single short branches, their 

 extremities being usually pointed, and in some species, as T. fallax, long and attenuated. 

 The length of the free tubes varies usually between -3 mm. and 7 mm., the average 

 thickness being from 5 to 7 n ; longer and much shorter tubes occur here and there. 

 The transverse section is usually circular. Their contents appear to be pellucid, but 



