4 o6 BOTANICAL GAZETTE [November 



of definite and conspicuous conceptacles, even though scattered 

 indefinitely over the entire thallus, places it more closely with the 

 Fucaceae. There seems no good reason for placing Splachnidium 

 (13) with the Ectocarpaceae. 



Summary 



1. The initial row of S plachnidium is similar in origin and 

 development to the "initial" of the Fucaceae, except that in 

 S plachnidium it involves an entire linear row of thallus tissue; 

 it may or may not include a terminal hair; and it accompanies 

 vegetative as well as reproductive activity. 



2. It seems unwise to place S plachnidium under a separate 

 family; rather is it preferable to retain it under the Fucaceae, 

 regarding it as a primitive member of that group for the following 

 reasons : (a) it closely resembles the Fucaceae in the structure of the 

 thallus, but has an apical meristem in place of a segmenting apical 

 cell with consequent dichotomy; (b) true conceptacles are present 

 which in origin and development are of the same general type 

 as those of the Fucaceae, but are scattered indefinitely over the 

 entire plant body; (c) the reproductive sacs may prove to contain 

 isogamous gametes. 



Acknowledgment is due to Professors John M. Coulter and 

 Charles J. Chamberlain for their suggestions and criticisms. 



University of Chicago 



LITERATURE CITED 



1. Agardh, J. G., Species, genera, et ordines Algarum. London. 1848. 



2. Drew, G. H., The reproduction and early development of Laminaria 

 iigitata and L. saccharina. Ann. Botany 24:177-190. pis. 14, 15. 1010. 



3. Greville, R. K., Algae Britannicae. Edinburgh. 1830. 



4. Harvey, W. H., Phycologia australica. London. 1858-1863. 



5. Hooker, J. D., Handbook of the New Zealand flora. London. 1867. 



6. Kjellman, F. R., in Engler and Prantl's Die natiirliche Pflanzen- 

 familien i 2 :Leipzig. 1897. 



7. KtiTziNG, F. T., Phycologia generalis. Leipzig. 1843. 



8. Laing, R. M., Observations on the Fucoideae of Bank's Peninsula. Trans, 

 and Proc. New Zealand Inst. 18:303-311. pi. 10. 1885. 



