COLEOCHJETE. 



COLEOSPORIUM. 



134. 



Fig. 136. 



Fig. 135. 



tinct, pedicel generally branched, bright 

 green ; length 1-800". Other species ; 

 mostly on Entomostraca (Ehr. Inf. 115 ; 

 Kent, Inf. 393). 



COLEOCHJE'TE, De Brebiss. A genus 

 of ChastophoraceEe (Confervoid Algae), of 

 which one species, C. scutata, is apparently 

 pretty common in freshwater pools, forming 

 minute green disks (fig. 134) adhering to 

 leaves, to the larger Confervas, sticks, &c., I 

 also to the sides of glass vessels in which 

 aquatic plants are kept growing. The disks 

 are formed of a number of dichotomous 

 filaments radiating from a central cell and 

 cohering laterally, the whole being closely 

 applied on the surface of support, so that 

 the discoid form is occasionally modified by 

 this (we have seen it forming a kind of cup 

 and irregular fan-like lobes, on the ends of 

 the articulations of Hydrodictyori) . In cer- 

 tain cases the filaments are more or less free 

 from their lateral union. From the back of 

 many of the cells projects a long, tubular 



Coleochsete scutata. 



Fig. 134. A perfect plant. Magnified 25 diameters. 



Fig. 135. Cells with tubular processes from the back 

 of the frond. Magnified 50 diameters. 



Fig 136. Commencement of the development of a 

 young frond. Magnified ICO diameters. 



process (fig. 134), with a bulbous base. Re- 

 production by zoospores ; and by fertilized 

 resting-spores (oospores). The former are 

 produced singly in the cells, from the whole 

 contents ; bear two cilia, and break out at 

 the back of the cell in C. scutata, from the 

 side in C. pulmnata. The resting-spores are 

 formed in cells near the margin, in penulti- 

 mate cells of the radiating filaments ; on the 



back, therefore, in C. scutata, at the ends 

 of the branches in C. pulmnata. These en- 

 large very much, and become surrounded by 

 a kind of rind or cellular coat, through 

 growth of cellular branchlets from the pre- 

 ceding and the surrounding cells, which 

 branchlets meet and enclose them. The 

 sporanges, with their trichogynes open at 

 the end, receive the spermatozoids, and 

 their contents are then converted into 5-8 

 resting-spores. The resting-spores do not 

 directly form new plants, but numerous 

 swarm-spores, and exhibiting alternations 

 of generations : the first swarm-spores pro- 

 duce only asexual plants, with repeated 

 broods of swarm-cells; finally comes asexual 

 generation, monoecious or dioecious accord- 

 ing to the species ; and then the spores or 

 oogonia. The antheridia are flask-shaped 

 cells, situated near the sporanges , the sper- 

 matozoids are biciliated, one in each cell. 



C. scutata, De Breb. (fig. 134) ; =P%/- 

 lactidium,Kutz. Fronds discoid, sporanges 

 on the back. On aquatic plants, &c., com- 

 mon. A variety, /3 soluta, occurs with the 

 radiating filaments more or less free. 



C. pulmnata, Braun. Fronds composed 

 of tufted-branched, radiating, free filaments ; 

 sporanges globose, at the ends of the fila- 

 ments. Chatophora tuberculata, 0. Mull,, 

 according to Kiitzing. 



Rabenhorst describes 7 species. 



BIBL. De Brebisson, Ann. tic. Nat. 3 ser. 

 i. 29, pi. 2 ; Ralfs, Ann. N. H. xvi. 309, 

 pi. 10; Hass. Ala. 217, pi. 77; Braun, 

 Rejuv. (Ray Soc. 1853) ; Kiitzing, Sp. Ala. 

 424; Miiller, Regensb. 'Flora,' xxv. B. ii. 

 513, pi. 3; Pringsheim, Jahrb. 1860, ii. 1 ; 

 Rabenh. Flor. Alg. iii. 388; Sachs, Bot. 

 289. 



COLEOP'TERA. The 1st order of 

 Insects, containing the beetles. See Lsr- 

 SECTS. 



COLEOSPO'RIUM, Leveille. A genus 

 of Uredinei (Hypodernious Fungi), sepa- 

 rated from Uredo, which proves to be a 

 secondary form of many distinct and inde- 

 pendent plants (see UE'EDO). These fungi, 

 which may be well observed in C. sene- 

 cionis, Schlecht., and other common spe- 

 cies, appear as yellow, reddish, or brown- 

 ish pulverulent spots upon the leaves of 

 living plants. Their mycelium, creeping in 

 the intercellular tissues 'of the plants upon 

 which they are parasitic, consists of deli- 

 cate branched filaments, which collect toge- 

 ther at certain points, become interwoven, 

 at the same time acquiring orange or yellow 



