. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . and antheridia. The sexual organs are developed atscattered intervals along the cylindrical filaments, and, except in the 1 Kiitziug (Tub. Plnjc. iv, t. 98) figured this state of Vauclieria as Gonyrosira dichotoma, anunfortunate error which has given rise to much confusion, since it has, of course, no relationshipwith the species of the true Gongrosira (a genus of the Ulotrichales). Consult G. S. West, 04,p. Ill ; and Herring, 07, p. 116. Kii
. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . and antheridia. The sexual organs are developed atscattered intervals along the cylindrical filaments, and, except in the 1 Kiitziug (Tub. Plnjc. iv, t. 98) figured this state of Vauclieria as Gonyrosira dichotoma, anunfortunate error which has given rise to much confusion, since it has, of course, no relationshipwith the species of the true Gongrosira (a genus of the Ulotrichales). Consult G. S. West, 04,p. Ill ; and Herring, 07, p. 116. Kiitzing recorded the fact that his Gongrosira grew intotilaments of Vancheria. Vaucheriacese 247 dioecious species, the oogonia and antheridia usually arise side by side on thesame filament (fig. 159 A and 7>) or on short lateral branches (figs. 157 H;159 C and D). The oogonia, which are developed either as lateral outgrowthsof the filaments or terminating short branches, swell out and assume a moreor less rounded or ovoid form and are then cut off by a basal septum. Theapex of the oogonium generally develops a rostrum or beak, which is in most o. Fig. 160. 1—3, 5—10, Vaucheria sessilis (Vauch.) DC. 1, .young sexual organs; 2, partiallyripe antheridium ; 3, transverse section of same ; 5, almost ripe sexual organs ; 6, the sameat the moment of fertilization ; 7, longitudinal section through a young oogonium, in whichthere are many nuclei; 8, older oogonium cut off from the filament by a wall, with only onenucleus (ek); 9, fertilized egg; 10, ripe zygote (oospore) and decayed , antherozoids of V. synandra Woron. a, antheridium ; ek, nucleus of oosphere (egg-cell);k, nuclei; o, oogonium ; oe, oil drops; pi, plasma-secretion from the oogonium; sk, nucleiof spermatozoids (antherozoids); sp, spermatozoids (antherozoids). (After Oltmanns.) cases turned to one side, either towards the antheridium or away from protoplasm of the oogonium contains much oil,
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