32 THE NORTH AMERICAN SLIME-MOULDS 



capillitium calcareous throughout. Forms occur and are included 

 here, in which the capillitium, especially in some parts, is physarum- 

 like, physaroid. Nevertheless, the distinctions hold good as a rule, 

 and are at once diagnostic. 



In capillitial differentiation the badhamias are definite and beauti- 

 ful. The net in a typical species, as B. papaveracea, is throughout 

 uniformly evenly tubular, the calcareous deposits delicate in the ex- 

 treme, presenting, as the spores disappear, an elegant trabecular 

 structure as if to support the persisting peridium if not the original 

 content. In other forms the capillitium is physaroid, with swollen 

 nodes, but heavily calcareous but not quite throughout. Badhamia, 

 Physarum, Tilmadoche, Craterium present a consistent group, of 

 which Physarum is the generalized expression. 



Berkeley's idea of the genus was expressed as follows: "Peridium 

 naked or furfuraceous. Spores in groups, enclosed, at first, in a hya- 

 line sack." Rostafinski, while accepting Berkeley's generic name, re- 

 defined it, emphasized the calcareous capillitium, and made reference 

 to the spore-adherence only to assert that Berkeley's description was, 

 in this particular, based on mistaken observation. In some species, 

 the spores do, in fact, show a tendency to cling together, a character- 

 istic which Badham was perhaps first to notice ; but that this is occa- 

 sioned by their being surrounded by a sac or common pellicle has not 

 been proved nor even suggested, by any subsequent investigator. 

 Berkeley's genus was therefore founded upon a slight mistake; but 

 w^e may conserve his rights in the premises if we write Badhamia 

 (Berk.) Rost., and so keep history straight. 



Key to the Species of Badhamia 



A. Spores ovoid or ellipsoidal 



a. Spores free 1. B. ovispora 



b. Spores adherent 2. B. versicolor 



B. Spores spherical 



a. Sporangia yellow 



i. Spores free 3. B. decipiens 



ii. Spores adhering 4. 5. nitens 



b. Sporangia grey, spores free 



i. Always sessile 5. S. panicea 



