CULTURE AND MORPHOLOGY 91 



Other investigators), the results obtained in general have not been 

 as significant as those in the green and especially the brown algae. 

 From the following review of a few of the more outstanding 

 contributions it will be apparent, however, that rich rewards may 

 be in store for those who resort to cultural methods in studies 

 dealing with problems in the morphology and taxonomy of red 

 algae. 



In a recent issue of Nature, Drew (1949) reported upon some 

 very interesting observations on the development, in culture, of 

 the spores of Porphyra. She found that the spores gave rise to 

 filamentous stages which, if allowed to grow on mollusc shells, 

 produced growths that in every respect resembled diose of the 

 heretofore accepted monotypic genus Conchocelis (fig. 6). From 

 this she concludes that this alga of uncertain systematic position 

 represents a phase in the life history of Porphyra. 



It is not clear from the account of Drew whether she was 

 culturing the monospores or the carpospores of Porphyra, but in 

 the light of earlier studies by Reinke (1878), Berthold (1881), 

 Kylin (1921, 1946), Ueda (1929), Rees (1940) and others on Por- 

 phyra and Bangia it seems safe to conclude that she was dealing 

 with carpospores. From the work of these investigators it is 

 known that the monospores give rise directly to new plants of 

 Porphyra or Bangia, whereas the carpospores produce filamen- 

 tous stages (not previously associated with Conchocelis) which 

 presumably form monospores whereby the Porphyra- or Bangia- 

 stages are reestablished. Dangeard (1931) has illustrated stages 

 which indicate that in certain instances the filamentous phase 

 of Porphyra, however, directly produces Porphyra plants as out- 

 growths from the filaments. 



In Drew's cultures the Porphyra-stdigt had not yet been re- 

 established, but the study is still in progress and it is to be hoped 

 that definite information will be forthcoming on this controver- 

 sial point. In this conection, it is of interest to note that Jao (1937) 

 has given some very convincing evidence of the formation of 

 monosporangia by Conchocelis (fig. 6). 



Observations which in some respects are even more remark- 

 able than those of Drew also have been made by J. and G. Feld- 



