54 NATURAL SCIENCE. Jan.. 1894. 



examines and describes the sori of these forms in the Hght of what 

 has been already done. 



The questions to be answered, if possible, appear to me to be 

 these : — 



Are the Fucaceous conceptacles and cryptostomata the descendants 

 of similar bodies evolved by ancestors approaching the Laminarian 

 type, in which we see them now dying out ? Is the Laminarian sorus 

 a mere flattened-out conceptacle ? or, have such shelters for spores, 

 antheridia and oogonia, for they are merely that, been evolved 

 independently of each other by these different types under a common 

 necessity of protecting their spores, etc. ? Do we now witness 

 nascent or dying efforts to produce conceptacles in such forms as 

 Adenocystis and Hydroclathrus ? Are the barren cryptostomata of 

 Saccorhiza prophetic or ancestral structures ? 



Their further examination, at all events, cannot fail to throw 

 light where it is much needed — on the relationships of the Natural 

 Orders of Phaeophyceae. 



REFERENCES. 



1. Bower, F. O. — On the Development of the Conceptacle in the Fucaceae. 



Quart. Journ. Micro. Set., 1880, p. 36. 



2. Oltmanns, F. — Beitrage zur Kenntniss der Fucaceen. Bibliotheca Botanica. 



Heft no. 14. Cassel, 1889. 



3. Barton, £!. S. — A Systematic and Structural Account of the Genus Turbinaria. 



Linn. Soc. Trans. Bot., 2nd ser., vol. iii., part 5, 1891. 



4. Mitchell, M. O., and Whitting, F. G.— On Splachnidium rugosiim Grev., 



the type of a new Order of Algae. Murray's Phycological Memoirs, pt. i, 1892. 

 Dulau & Co. 



5. Mitchell, M. O. — On the Structure of Hydroclathrus. Ibid., pt. ii., 1893. 



6. Murray, George. — On the Cryptostomata of Adenocystis, Alaria, and Sac- 



corhiza. Ibid. 



E. S. Barton. 



