ARTIIONIA. 



ARTHROCLADIA. 



arteries of other mammals, the internal coat 

 contains unstriped muscular fibres. This is 



Fig. 36. 



Magnified 30 diameters. 



Transverse section of the human aorta below the superior mesenteric artery, 

 after acetic acid. 1. Inner coat: a, epithelium; b, striated layers; e, elastic 

 layers. 2. Middle coat : d, its elastic layers; e, the muscular and areolar tis- 

 sues ; 3, outer coat with its network of elastic tissue. 



kind of velvety surface ; spores numerous, 

 angular, or like a double cone, attached in 

 whorls at the joints of the 

 filaments. 



BIBL. Berkeley, Ann. 

 Nat. Hist. i. 436 ; Torula 

 Eriophori, Berk. English 

 Flora, v. p. 2. 35.9. 



ARTHROBOTRYS, 

 Corda. A genus of Mu- 

 cedines (Hyphomycetous 

 Fungi) bearing elegant no- 

 dular groups of septate 

 spores. No species is yet 

 recorded in Britain. Corda 

 describes one species, A. 

 superba (fig. 37) ; in this 

 the spores are about 1 - 1 500" 

 long. Fresenius describes 



the case also with the outer coat of the larger 

 arteries in animals, but not in man. 



All except the smallest arteries are fur- 

 nished with nutrient blood-vessels, the vasa 

 vasorum-, these ramify principally in the 

 outer coat, in the larger ones extending into 

 the middle coat. They also receive branches 

 of the sympathetic and spinal nerves. 



The most important pathological changes 

 to which the arteries are subject, consist of 

 the deposition of fat in their substance 

 fatty degeneration, and of atheromatous 

 matter. These will be noticed under the 

 heads FATTY DEGENERATION and ATHE- 

 ROMA. See also VESSELS. 



BIBL. Henle, Allgemeine Anatomie ; K61- 

 liker, Handbuch der Gewebelehre ; Wedl, 

 Grundzuge der pathol. Histol. ; Rokitansky, 

 Ueber einige d. wichtig. Krankh. d. Arterien. 



ARTHONIA, Acharius. A genus of Gra- 

 phideae (Gymnocarpous Lichens), distin- 

 guished by the small roundish or irregular 

 apothecia, scattered over the thallus, devoid 

 of an excipulum. Mr. Leigh ton describes 

 eight British species, growing on the bark of 

 trees, some of which have been described by 

 others as species of Opegrapha, &c. 



BIBL. Leighton, Ann. of Nat. Hist. Ser. 2, 

 vol. xiii. p. 436. pi. 7. 8. 1854. 



ARTHRINEUM, Kze. A genus of De- 

 matiei( Hyphomycetous Fungi), of which one 

 species has been found in Britain, growing 

 upon dead leaves of Eriophorum angustifo- 

 lium. 



A.Puccinoides, Kze. Filaments elongated, 

 tufted, often not more than 1-50" long, but 

 frequently confluent in a linear form, with a 



Fig. 37. 



Fig. 38. 



Arthrobotrys superba. 



37. A fertile filament with many groups of spores. 



Magnified 200 diameters. 



38. A fertile articulation of ditto, with most of the 



spores detached from the spine-like pro- 

 cesses on which they are borne. 

 Magnified 600 diameters. 



another, A. oligospora, perhaps not distinct, 

 which has the erect filaments about 1-50" 

 high, solitary, not in tufts, and mostly with 

 only one group of spores ; these are pear- 

 shaped, 1-700' long, and have the septum 

 below the middle : it was found on damp 

 wood, fruit and earth, in a fungus-bed. See 

 FUNGUS-BED. 



BIBL. Corda, Prachfl. eur. Schimmelb. p. 

 43. t. 21 ; Fresenius, Beitr. zur Mycologie, 

 Hefti.p.18. pi. 3. figs. 1-8. 



ARTHROCLADIA, Duby. A genus of 

 Sporochnaceae (Fucoid Algae). A. villosa, 

 Huds., is a rather rare British annual sub- 

 marine species, growing in 4 to 5 fathoms 



