PUNCTARIA. 



[ 545 ] 



PYOID CORPUSCLES. 



489; Bouche, Nov. Act. Nat. Cur. 1835. 

 xvii. 501 ; Duges, Aim. d. Sc. nat. 1832. 

 xxvii. p. 165 ; Gervais, Walckenaer's Apt. 

 iii. 362; Denny, Ann. Nat. Hist. 1843. xii. 

 315. 



PUNCTARIA, Greville.— A genus of 

 Pimctariacea3 (Fiicoid Algae), containing 

 three (one doubtful) British species, P. lati- 

 folia, plantaginea and tenuissima, growing 

 on rocks and stones, consisting of membra- 

 nous, olive or brown, ribless fronds, 4 to 12" 

 long, 1 to 3" broad, having a shield-hke 

 organ of attachment at the base. The fruc- 

 tification consists of sori scattered all over 

 the frond in minute distinct dots, composed of 

 roundish oosporanges (producing zoospores) 

 intermixed with paraphyses ; these sporanges 

 are called spores in most works. No other 

 form of fructification has yet been observed. 



BiBL. Harvey, Brit. Mar. Alg. p. 41. 

 pi. 8 B, Phyc. Brit. pis. 8, 128, 148; Greville, 

 Alg. Brit. pi. 9. 



PUNCT^TIIACE^.— A family of Fu- 

 coideae. Root a minute naked disk, frond 

 cylindrical or flat, unbranched, cellular; with 

 ovate oosporanges intermixed with jointed 

 threads in groups on the surface. 



Synopsis of the British Genera. 



I. PuNCTARiA. Frond flat and leaf-like. 

 Oosporanges scattered or in sori. 



II. AsPEROcoccus. Frond membranous, 

 tubular, either cylindrical or compressed. 

 Oosporanges in dot-like sori. 



III. LiTosiPHON. Frond cartilaginous, 

 filiform, subsolid. Oosporanges scattered, 

 almost solitary. 



PUS. — Popularl}^ knowTi as " matter." 

 One of the products of inflammatory exuda- 

 tion. 



Its general properties are too well known to 

 require description. Pus consists of an albu- 

 minous liquid, containing a number of 

 minute corpuscles in suspension. These con- 

 sist of molecules and granules, composed of 

 proteine-compounds, fat or the earthy phos- 

 phates; globules of fat of verj^^arious sizes; 

 and the proper pus-corpuscles. Pus-cor- 

 puscles (PI. 30. fig. 4) are spherical, from 

 1-2500 to 1-2000" in diameter; presenting 

 a granular appearance on the surface, and 

 containing a number of larger or smaller 

 granules and a small quantity of liquid. The 

 granular appearance of the surface arises 

 from the internal granules pushing out, as 

 it were, the cell-wall, for it disappears when 

 the cell-wall is distended and separated from 



the granules by the action of water or very 

 dilute solution of potash. When treated 

 with acetic acid, the cell-wall and granules 

 become excessively transparent and ulti- 

 mately vanish (PI. 30. fig. 5), leaving from 

 one to five, generally two or three, round or 

 oval nuclei, which mostly present a dark 

 margin and light centre, giving them a 

 cupped appearance, indicating a diminution 

 of refractive power in the centre, arising 

 fi'om either a depression on the surface or the 

 existence of a vacuole. The cupped centre 

 is sometimes seen in the nuclei without 

 acetic acid, after the action of water only. 



In the pus of chronic abscesses, unhealthy 

 ulcers, &c., the corpuscles are often few, 

 deformed and mixed with numerous granules 

 of proteine, fatty and calcareous matters, 

 crystals of cholesterine, of the ammonio- 

 phosphate of magnesia, and sometimes 

 monads and vibrios; exudation-corpuscles 

 are occasionally present also. 



Pyoid corpuscles. — Under this term, 

 Lebert describes a modification of pus-cor- 

 puscles, consisting of a tolerably transparent 

 envelope, enclosing from eight to ten or 

 more small globules (PI. 30. fig. 6). Acetic 

 acid does not alter them, or at most only 

 renders them slightly more transparent. The 

 small globules are composed of a proteine- 

 compound, for they are soluble in potash. 



BiBL. That of Chemistry, Animal ; 

 and Lebert, Phys. Pathologique. 



PYCNIDIA.— A term applied by Tulasne 

 to the receptacles enclosing stylospores in 

 the Lichens and Fungi. 



PYCNOPHYCUS, Kiitz.— A genus of 

 Fucacea^ (Fucoid Algae), containing one 

 British species, P. (Fucus) tuherculatus, 

 removed from Fucus on account of its cylin- 

 drical frond, the compact cellular substance 

 of the receptacles and the ramified fibrous 

 pseudo-root. The fructifications, formed at 

 the ends of the dichotomous lobes of the 

 frond, are of elongated form, cylindrical, 

 more or less tuberculated, and exhibit 

 numerous pores opening from conceptacles, 

 containing spore-sacs and antheridia (to- 

 gether), resembling in general those of Fucus. 

 The spore-sacs are collected at the bottom 

 of the conceptacles, the antheridia at the 

 upper part. For the details respecting the 

 spores and spermatozoids see Fucus. 



BiBL. Harvey, Brit. Mar. Alg. p. 18. 

 pi. 2 A, Phyc. Brit. p. 89; Decaisne and 

 Thuret, Ann. des Sc. nat. 3 ser. iii. p. 5, 

 &c., pi. 1 ; Thuret, ibid. xvi. p. 10. 

 PYOID CORPUSCLES. See Pus. 



2n 



