1915] Skottsbery: J'ljlaidla Poslclsiae 159 



serve exactly the same purpose as the lt»im ones. It does not require 

 much imagination to derive the BacJtclotIa type fr-om I'anthocarpus, 

 and the same may perhaps be said of the other Pylaiellae. It is doubt- 

 ful whether we should regard the continuous chains or the intercalary 

 ranges of sporangia as the more primitive type. To me the latter 

 seem to represent a slightly more advanced .stage, a step towards the 

 origin of special reproductive organs. In Pijlaiella varia we can almcst 

 speak of such ; in Ectocarpus they have assumed a more distinct shape. 

 If, in /'. Fostelsiae, the long threads should remain sterile and the 

 short branches alone become fertile, we woidd come near the type of 

 /'. raria, and if the branches were of a more uniform length we should 

 get a Euectocarpus. It is hardly necessary to mention that, with 

 these ideas, I do not at all pretend to unravel the phylogeny of these 

 forms. 



It was Professor W. A. Setchell who kindly drew my attention to 

 the snuiU alga described above. I use this opportunity to thank him 

 in i)ublic for the hospitality he showed me during my stay with him 

 in California. The success I had in collecting and getting acquainted 

 with the magnificent marine vegetation of the Pacific Coast was almost 

 entirely due to his kind and utterly unselfish assistance. 



Transmitted February 19, 1915. 



