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434 BOTAXICAL GAZETTE [june 



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There were a few plants in the collection made on April 12 which 

 bore no reproductive organs; these were probably female plants 

 in which the carpogonial branches had not yet been initiated. All 

 of the plants over 4 cm. in height, collected in June and July, with 

 the exception of 2 or 3 individuals bearing carpogonial branches, 

 bore either mature cystocarps or tetraspores. Hundreds of plants 

 were collected and a careful but entirely unsuccessful search was 

 made for individuals bearing spermatia. It seems evident from 

 these facts that the male plants are present for only 2 or 3 weeks in 

 April. It is possible, of course, that a few solitary individuals 

 were present in June and July. This view is supported by the fact 

 that it was possible to find on the female plants collected during 

 this time all stages from the 1 -celled carpogonial branch to the 

 mature cystocarps. The cystocarpic plants reach their maximum 

 development in the early part of June and have completely dis- 

 appeared by the middle of July. The tetrasporic plants attain 

 their maximum development in the latter part of June, although j 



plants 19 cm. in height were very abundant as early as June 12. 

 A few tetrasporic plants persist until late in August, but they are 

 rare even in the latter part of July. The tetrasporic and female 

 plants in all the red algae seem to be more numerous than the male 

 plants. The experiments of Lewis (7) with Griffithsia Bometiana 

 and Dasya elegans indicate that in both of these species the tetra- 

 spores form equal numbers of male and female plants. This is 

 probably true of Dumontia and other members of the Florideae. 

 The apparent scarcity of male plants may be due to the fact 

 that in some forms they are exceedingly small and therefore 

 are easily overlooked. This would not apply to such forms as 

 Dumontia, however, in which the difference in the average height 

 of the male and female plants is not more than 4-5 cm. Svedelius 

 (14, 16) reports that the male plants of Martensia and Delesseria 

 die shortly after they have discharged their spermatia. This is 

 probably true of the Dumontia plants also. Lewis (8) has found 

 that the tetrasporic plants of most of the red algae at Woods Hole 

 are very abundant in July. The tetraspores germinate to form 

 cystocarpic plants from which carpospores are released in Sep- 

 tember. The holdfasts of young sporelings formed from these 



