PALMELLACEZ, 138 
boiled vegetables, or even decaying Agarics, is quite astonishing, making 
them appear as if spotted with arterial blood; and what increases the 
illusion is, that there are little detached specks, exactly as if they had 
been squirted in jets from asmall artery. The particles of which the 
substance is composed have an active molecular motion, but the mor- 
phosis of the production has not yet been properly observed, and till 
that is the case it will be impossible to assign its place rightly in the 
vegetable world. Its resemblance to the gelatinous specks which occur 
on mouldy paste, or raw meat in an incipient state of decomposition, 
satisfy me that it is not properly an Alga.” Mr. H.O. Stephens, on 
the other hand, contends that it is an Algoid production. After nar- 
rating its history (see “Ann. Nat. Hist.,” 1853, p. 409), he says—“T 
observed at table the under surface of a half-round of boiled salt beef, 
cooked the day before, to be specked with several bright carmine- 
coloured spots, as if the dish in which the meat was placed had con- 
tained minute portions of red currant jelly. On examination the next 
day, the spots had spread into patches of a vivid carmine-red stratum of 
two or more inches in length. 
“ With a-simple lens the plant appears to consist of a gelatinous sub- 
stratum of a paler red, bearing an upper layer of a vivid red hue, hav- 
ing an uneven or papillate surface. The microscope shows this stratam 
to consist of generally globose cells immersed in or connected by muci- 
laginous or gelatinous matter. The cells vary in size, and contain red 
endochrome. As far as I can observe they consist of a single cell- 
membrane, and contain a nucleus. Treated with sulpho-iodine, they 
become blue. In my judgment this plant is a Palmella closely allied to 
P. cruenta, but certainly distinct, the cells or granules of the latter 
differing from it not only in their colour but size.” The memoir also 
contains observations on the great vitality of this species, and other 
subjects connected therewith, to which the student is referred. 
Plate V. fig. 5. a, part of thallus, magnified 400 diam.; 6, portion 
magnified 800 diam. 
Genus 7. PORPHYRIDIUM. Wiig. (1849.) 
Thallus between gelatinous and membranaceous, somewhat 
incrusting, long and broadly expanded, composed of globose or 
many-sided cells. Multiplication of the cells by alternate di- 
vision in all directions. Propagation unknown. 
This genus is placed by some authors in Porphyracea, near the genus 
Bangia, in the class Rhodophycee (see Rabh. Alg. iii. 397), but we prefer 
to retain it near the old genus Palmella, in which it was previously in- 
cluded, and to which it seems to be most naturally allied. 
Porphyridium cruentum. Wag. Hinz. Aly. t. 4H. 
Thallus dark purplish-red, gelatinous ; cells angular or 
rounded. : 
Size, -007-01 mm. (Rabh.), 0965-009 mm. (Kirch.). 
Kirch. Alg. Schl. p. 111. Rabh. Alg. iii. 897. 
Palmella cruenta, Ag. Syst. p. 15. Rabh, Exs. No, 14 and 
1071. Hass. Alg. p. 308, t. 80, f. 5. 
Tremella cruenta, Eng. Bot. t. 1800. Grev. Se. Crypt. Fl. 
pl. 205. : 
On the naked ground, moist walls, &c, Common throughout 
Europe. 
