Reprinted from the "Annals of Botany.' Vol. XIII. 



ON ACTINOCOCCUS AND PHYLLOPHORA. 



By Otto Vernon Darbishirb, The Owens College, Manchester, 



With Plate XVII. and seven Figures in the Text. 



Credidi enim et eliamnunc credo, tubercula ilia nihil aliud esse quam para- 

 siticum quid . . . — Lyngbye, Tentamen Hydrophyt. Dan., 1819, p. 11. 



In 1893 Schmitz published a paper, in which he discussed at some 

 length the Actinococcus question. He maintained that all so-called 

 forms of fructification of Phyllophora Brodiaei (Turn.) J. Ag. which he 

 had so far been able to examine, belonged in reality to a different 

 Floridea growing parasitically on the former species (5, p. 371). This 

 paper was shortly after reviewed by Gomont, who expressed his full 

 agreement with the views held by Schmitz ; so that the true nemathecia 

 of Phyll. Brodiaei (Turn.) J. Ag. still remained to be found. 



Doubts had long been felt with regard to the true nature of the so- 

 called nemathecia of Phyll. Brodiaei (Turn.) J. Ag. The few lines 

 quoted at the head of this paper were written by Lyngbye in 1819 in 

 describing these very same nemathecia. In the beginning of 1894 the 

 author of this paper gave a preliminary account of some observations 

 on the anatomy and development of the Baltic species of Phyllophora 

 Grev., in which Schmitz' assertions concerning the parasitic nature of 

 the nemathecia of Phyll. Brodiaei (Turn.) J. Ag. were discussed and 

 the accuracy of his conclusions was doubted (1, p. 47). A more detailed 

 account of the author's work on the Baltic Phyllophorae was published 

 about a year later, but unfortunately Schmitz died in 1894. In the 



