ORGANIZATION. 



[ 658 ] 



ORIBATEA. 



BIBL. D'Orbigny, For. VienS22; William- 

 son, Eec. For. 2; Carpenter, For. 176; 

 Alcock, Mem. Lit. Phil. Manch. 3. iii. 178 j 

 S. Owen, J. Linn. Soc. Zool. ix. 149; Ter- 

 quem, Mem. Metz, 1862, 432; Brady, Qu. 

 Mic. Jn. n. s. xix. 75. 



ORGANIZATION AND VASCULA- 

 RIZATION. Immediate reunion of cut 

 surfaces may take place without any exuda- 

 tion ; but in healing by what is termed the 

 first intention, a substance is present which 

 glues the edges of the wound together. 

 This consists of the connective tissue of the 

 cut surface, infiltrated with blood-corpuscles 

 and serum, and swollen by the imbibition 

 of the latter. The next stage of the pro- 

 cess is the migration of colourless corpuscles 

 from the dilated vessels in the immediate 

 neighbourhood. They permeate the whole 

 of the cementing medium and the adjacent 

 connective tissue, so that the divided parts 

 are at length united by a continuous layer 

 of embryonic tissue. The next step is the 

 reestablishment of the circulation. Thiersch 

 found the cut ends of the vessels a few 

 hours after the injury plugged by a cor- 

 puscular proliferation and somewhat dilated, 

 but seldom occupied by a blood-clot. In- 

 jecting the vessels at this stage with a warm 

 solution of gelatin, and hardening the speci- 

 men in alcohol, he found sticking to the 

 surface of the club-shaped plug of gelatin, 

 endothelial cells, some detached and isolated, 

 others undergoing proliferation. Moreover 

 he found a peculiar configuration of the 

 surface of the plug, in which were the 

 radicles of a very beautiful system of inter- 

 cellular canals, forming a provisional nu- 

 trient apparatus. The last act is the trans- 

 formation of that part of the embryonic 

 tissue which is not employed in the con- 

 struction of vessels, into fibrous connective 

 tissue. Should pus be formed in a wound, 

 healing by the second intention occurs (see 

 Pus). Pus is given ofi' from the wound, 

 and from its surface young cells force their 

 way from countless points ; they are accom- 

 panied by a fluid mainly transmitted from 

 the blood, and very rich in dissolved al- 

 buminous matters. Sooner or later the cells 

 close up their ranks, and a layer of em- 

 bryonic tissue is formed, which intervenes 

 between the parenchyma of the organism 

 on the one hand and the pus on the other. 

 Then this embryonal connective tissue gets 

 thicker, rises into small globular projections 

 or granulations ; they produce both skin and 

 cuticle, and new vessels. Along certain 



lines running through the parenchyma in 

 which these new vessels are to be, a closer 

 aggregation of the cells becomes apparent; 

 a cord or row of cells becomes visible, 

 pointing out the form and direction of the 

 future blood-path. Soon the blood makes 

 its appearance in the axis of the cellular 

 cord, and the cells parted asunder begin to 

 constitute the wall of a new blood-vessel. 

 As each layer of embryonal tissue is formed 

 on the surface, rows of cells aggregate as 

 above, and new vessels are completed. As 

 the cicatrical tissue contracts after its for- 

 mation out of the embryonal tissue, and as 

 it is fashioned at the deepest part of the 

 wound, first the whole of the raw surface 

 shrinks and compresses the vessels, obliterat 

 ting many and reducing the vascularity of 

 the healing tissues. 



ORIB'ATA, Latr. A -genus of Oriba- 

 tidae, of which there are several species, on 

 stones and plants. Some are common. 



The position of three species is doubtful, 

 viz. Acarus conferva, Schr., freshwater, 

 creeping upon Confervas, &c. ; Oribata de- 

 mersa, Duj., with a cervical eye, upon 

 Hypnum inundatum ; and Oribata marina, 

 a marine species. 



BIBL. Gervais, Walck. Apt. iii. 251 ; 

 Schrank, Ins. Austria, 611 ; Duiardin, 

 rinstit. 1842, 316; Koch, Deutschl. Crust.-, 

 Duges, Ann. Sc. Nat. 2. stSr. ii. 46 ; Murray, 

 EC. JSnt. 217. 



ORIBATEA. A family of Acarina. 



Char. Body covered by a hard horny 

 dark envelope; palpi fusiform, 5-jointed ; 

 first joint small, second large, inflated and 

 almost half the length of the entire palpus, 

 palpi hairy outside only ; mandibles chelate; 

 body often winged ; no suckers. Genera : 



Nothrus. Body elongate, irregularly 

 quadrilateral, with spinous filaments; legs 

 of moderate length, thick, tarsi with 3 

 homodactyle claws. 



Belba. Abdomen distinct from thorax, 

 rounded, inflated; legs long, geniculate, 

 with 1 claw. 



Oribata. Cephalothorax with lamellar 

 appendages ; tarsi with 3 heterodactyle 

 claws ; hairs bristle-shaped. 



Cepheus. Cephalothorax lamellar : claws 

 3, alike. 



Notaspis. Cephalothorax lamellar, tectum 

 confounded with it. 



Leiosoma. Cephalothorax with plates, 

 claws 3, heterodactyle. 



Pelops. Like Oribata, but hairs flat and 

 spatula-shaped. 



