VITT^E. 



[ 812 ] 



VOLVOCINE.E. 



VITT^E OF FRUITS. See SECRETING 

 ORGANS of Plants. 



VITTA'RIA, Sm. A genus of Grammi- 

 tidese (Polypodiaceous Ferns). Several 

 species ; tropical. (Hooker, Syn. 395.) 



VOLUTELLA,Fr. A genus of Stilbacei 

 (Hyphomycetous Fungi), comprising seve- 

 ral species of parasites which have been 

 variously distributed. The plants consist 

 of minute fleshy papillae (stromatd) of cel- 

 lular structure, the surface of which is 

 clothed with elliptic, oblong, or fusiform 

 stylospores, from between which project long 

 jointed hairs (fig. 806) traversing the stroma. 



Fig. 806. 



Volutella buxi. 

 Magnified 20 diameters. 



It may be desirable to give the synonymy 

 of these plants according to Berkeley and 

 Broome. 



V. ciliata, Fr. (Psilonia rosea, Br. Fl.). 

 Whitish or rosy ; on potatoes. 



V. buxi) Berk. & Br. (Fusisporium buxi, 

 Br. FL). White; on dry box-leaves (fig. 

 806). 



V. setosa, Berk. & Br. (Psilonia setosa, 

 Br. Fl. , JEgerita set., Grev.) . White, on wood 

 and herbaceous stems. 



V. hyacinthorum, Berk. &Br. (Psil. hyac., 

 Br. Fl.). White; stipitate ; on hyacinths 

 grown in water. 



V. melaloma, B. & Br. Orange, with 

 black hairs; on sedges. 



BIBL. Berk. Br. Fl ii. pt. 2. 352-3 ; Ann. 

 N. H. 2. v. 466, pi. 11. fig. 3; Greville, 

 Crypt. Fl. pis. 102 & 268. fig. 2 ; Corda, Ic. 

 Fung. ii. pi. 13. fig. 107 ; Fries, Syst. Myc. 

 iii. 447. 



VOLVOCIN'E^E. A family of Confer- 

 void Algaa; they were formerly included 

 among the Infusorial animalcules, among 

 which they form one of Ehrenberg's families. 

 The most striking general character of these 

 objects is their composition of individual 

 elements, which exhibit in their mature and 

 most perfect stage of existence, the charac- 

 ters of the transitory ZOOSPORES of the other 

 Confervoids. The Volvocinese may be cha- 



racterized as plants composed of a number of 

 permanently-active zoospore-like bodies 

 associated together into families of definite 

 form, in which the members, connected or 

 held together in various ways by cell-mem- 

 branes, retain their distinct individuality for 

 all physiological purposes of nutrition, 

 growth, reproduction, &c., but represent only 

 one being in relation to the surrounding 

 objects. Protococcus, however, consists of 

 only a single cell. The best-known and 

 most beautiful example of this family is the 

 genus Volvox (PI. 7. fig. 24), consisting 

 when mature of a spherical membranous 

 sac, at the periphery of which, within the 

 membrane, are arranged a large number of 

 zoospore-like bodies (^omY&a),each provided 

 with a pair of cilia, which pass out through 

 the enveloping membrane, collectively form- 

 ing a coating ah 1 over the external surface, 

 and by their vibration causing a rotary mo- 

 tion of the entire globe. 



The modes of reproduction of the Volvo - 

 cineae, both vegetative and by spores, are 

 described under PANDORINA, VOL vox, and 

 GONIUM; hence it is unnecessary to dwell 

 on them here. 



Char. Permanently active zoospore-like 

 bodies, ciliated (except Gyges), surrounded 

 by a gelatinous coat (like COCCOCHLORIS) ; 

 solitary or combined in definite groups, with 

 or without a common enveloping membrane. 

 Individuals pyriform, or with the body pro- 

 longed posteriorly. 



Solitary. 

 Without cilia 



r Protococcus. 



\ (Chlamidomonas.) 



With a pair of cilia 



Grouped. 

 Forming a square layer, goni- -. GoniwTOt 



dia with two cilia / 



Forming a spherical body. 

 Cilia solitary. 



With a " tail " Uroglena 



Without a " tail." 



With an eye-spot, go- ) 

 nidia dividing into > Sphcerosira* 

 clusters ) 



Cilia two. 



Without an eye-spot. . . Synura*. 

 With an eye-spot. 

 Common envelope spherical. 



Gonidia numerous, all \ ^ f .j nnr . 



over the periphery.../ V( 

 Gonidia eight, in a cii 



Common envelope ellipsoidal, gonidia sixteen 



or thirty-two Pandorina. 



* Probably stages of development of VOLVOX or PAN- 



DOBINA. 



