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 






RS 
L- 
2. 
on 
(le 
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x 
TO 
BNW 
—— 


FIG. 192. a, 5Arcyria tncarnata, P. inoutline. « a ripe spor- FIG. 193. a, 6 Trichia fallax, Fr. ahalf ofa 
angium closed. 5 the same open with the expanded net-work of capillitium-tube. 4 superficial view of a spore. 
the capillitium. ¢, d Arcyria Serpula, Wigd. (4. anomala, De ¢, @ Trichia chrysosperma, DC. De By. ¢ ex- 
Bary.) c portion of a capilitium. daspore. = and 5 magn. 20, tremity of a capillitium-tube. @ spore. Magn. 
¢ and d 390 times. 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, 4), 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 a; longer and much shorter tubes occur here and there. 
The transverse section is usually circular. Their contents appear to be pellucid, but 
