Page:Journal of botany, British and foreign, Volume 34 (1896).djvu/158

There was a problem when proofreading this page.
138
GUIDE TO THE BRITISH MYCETOZOA.

Stemonitaceœ, with typically separate sporangia, has a singular exception in the curious confluent condition of S. fusca (Mon. 110). In the genus Chondrioderma the position of C. Michelii arrests one's attention. The examination of some thousands of C. testaceum in the field suggests that C. reticulatum and C. niveum are the natural offsets of the former. At least these three have an interesting habit of commensalism suggesting community of descent, whilst C. Michelii is conspicuous by its absence. One learns, however,

Dianema depressum
Lister.


a. Plasmodiocarp. × 2.
b. Capillitium attached above and below to the walls of the sporangium. × 50.
c. Spore. × 560.

Badhamia utricularis
Berk.


a. Cluster of sporangia. × 3½.
b. Fragment of capillitium and spore-cluster. × 140.

Cienkowskia reticulata
Rost.


a. Part of branching plasmodiocarp. × 4.
b. Capillitium threads and part of a perforated lime-plate. × 140.

Lycogala miniatum
Pers.


a. Three æthalia. Nat. size.
b. Capillitium. × 150.
c. Spore. × 600.

Physarum nutans
Pers.


a. Two sporangia, × 9.
b. Capillitium threads, with lime-knots, attached to a fragment of the sporangium-wall. × 110.

Cribraria aurantiaca
Schrad.

a. Group of sporangia. × 2.
b. Sporangium after dispersion of the spores. × 20.


from Mr. Lister that American observers have "sent fine specimens of flat winding plasmodiocarps corresponding with Rostafinski's type of C. reticulatum, which Mr. Wingate (of Philadelphia) has found in company with the stalked C. Michelii." Here we might suggest that C. testaceum may be taken as a convenient centre from which the other forms diverge.

It is certainly agreeable to some of the workers in this field that many of the varieties named and described in the monograph have been omitted from the Guide. This course simplifies the subject considerably, without diminishing the practical value of the classification. Probably the most interesting portion to the ordinary