PENICILLIUM. 



[ 585 ] 



rEi»rEi{. 



many yeai-s ago, by Tiirpin, that P. (//(iiicitm i 

 is the last term ot' the growth both of the 

 true yeast-phiut {'Tonila Cerevidce) and of 

 the milk-yeast {Oidium lactis). We have 

 found the' gelatinous crusts of the vinegar- 

 plant to contain structures which represent 

 Toruki aud Oidium, and to grow like them ; 

 and we have also observed, iu repeated ex- 

 periments, that beer allowed to stand until 

 sour, at tir^t appears clothed with a whitish 

 mealy collection of minute vesicles, repre- 

 senting the ultimate stage of Torida, aud 

 subsec^uently this gradually gave place to 

 gelatinous matter, which at length covered 

 the whole surface with a tough him, and 

 fruited as Penicillium glaucum. Hence it 

 would appear that the yeast-fungus also 

 is merely a \egetative form of Fenicillium 

 developed under pecuhar conditions. This, 

 however, has been actually proved h\ 

 Berkeley and Iloffiuan (see '' Yeast," in 

 Black's ' Encyclopedia of Agriculture'). 

 More is said on this point imder Vixkc4AB- 

 Plant and Yeast. 



One of the species has become famous on 

 account of its extremely rapid occurrence 

 in Paris on the " pain de munition," where 

 the spores must have undergone a degree of 

 heat equal to that of boiling water. 



Several species are enumerated ; and we 

 have given under the separate head of 

 CoREMiUM a form which is merely a con- 

 fluent growth of Penicilliuni, producing a 

 compound pedicel. 



P. gJmicum, txrev. Mycelial filaments 

 form a crust-like web, spores green or 

 bluish. GreviUe, .b'c. Crypt. Fl. pi. 58. flg. 1. 

 P. crustaceum, Fries. Extremely com- 

 mon. 



P. candidian, Link. Mycelial filaments 

 woven together, spores white. (Distinct ?) 



P. sparsum, Grev. Mycelium lax, spores 

 white. Sc. Crypt. Fl. pi. 58. flg. 2. Per- 

 haps not different from the last. 



P. fasciculatum, Sommer. Mycelium 

 scarcely developed filaments aU fertile, 

 trifid at the apex, spores glaucescent. 



P. subtile, Berk. Extremely minute, my- 

 celium creeping, fertile filaments erect, sim- 

 ple or ternate : chains of spores few, spores 

 broadly elliptical. Ann. N. H. \i. pi. 14. 

 fig. 25. 



P. roseum, Link. Mycelium effused ; 

 fertile filaments slightly branched, spores 

 rose-colom\ 



One species (P. curtipes) has been found 

 in amber. 



BiBL. Berk. hook. Br. Flor. ii. pt. 2. 



Cells 

 trans- 

 Length 



844; Ann. N. 11. i. 202, vi. 437, 2. vii. 102; 

 Greville, loc. cit. ; Fries, ISyst. Myc. iii. 407 ; 

 Sum. Veyet. 489. See also Yeast and 

 Vinegar-Plant. 



PE'NIUM, J5reb.— A genus of Desmidi- 

 aceiB. 



Char. Cells single, entire, elongated, 

 straight, and slightly or not at all constrict- 

 ed in the middle. 



Sporangia round or quadrangular, smooth, 

 not spinous. 



At each end of the cells is a rounded 

 space containing moving molecules. 

 Several British species (Ralfs). 

 P. Brebissonii (PL 14. fig. 36). 

 smooth, cylindrical, ends rounded, 

 verse median baud inconspicuous. 

 1-640 to 1-400". 



Common. Sporangium at first quadrate, 

 but finally orbicular ; conjugating cells per- 

 sistent, or remaining permanently attached 

 to the sporangium. 



P. inaryaritaceum (PL 14. fig. :\7 , empty 

 cell). Cells cylindrical or fusiform, with 

 rounded truncate ends, and covered with 

 pearlv granules in longitudinal rows. Length 

 1-160": 



BiBL. Ralfs, Desmid. 148; Archer, Qu, 

 Mic. Jn. 1864, 179, 1867, 183 

 Alg. ; Rabenh. Alg. iii. 119. 



PENNAT'ULA, Cuv. (Sea-pen). — A 

 genus of Alcyonaria (Zoophytes). 



The spicula form interesting microscopic 

 objects. 



■PENTHALEUS, Koch. — A genus of 

 Trombidina (Acarina). Somewhat elon- 

 gate ; anterior legs rather long and slender ; 

 femora of hind legs thickened. P.hcematopus. 

 (Koch, Uebers. ; Murrav, Ec. Ent. 121.) 



PENTHALO'BES, Uyn:i\,=Meyamerus 

 ovcdis. 



^ PEPLONYS'SUS, Kol. — A genus of 

 Sarcoptidfe (Acarina). 2 species; yellow- 

 ish-brown ; on Nycteris and Rkinopoma ; 

 Egypt. (Kolenati, Sitz. Ak. Wien, 1858, 

 74 • Murray, Ec. Ent. 323.) 



PE FPER. — Black pepper consists of the 

 benies of Piper- nigrum ; white aud decor- 

 ticated pepper of the same berries with the 

 outer part of the coats removed. The cel- 

 lular tissues of the several lamellae of the 

 husk, and of the albumen or body of the 

 seed, are tolerably characteristic (PL 2. fig. 

 12) , and may be known by their appearance 

 under the microscope from the fragments of 

 linseed, mastard, &c. with which peppers 

 are sometimes adulterated. White pepper 

 is fraudulently reduced with flour, which 



, Hassall, 



