l60 THE ALGAE 



REFERENCES 



General 



Kylin, H. (1940). Lunds Univ. Arssk. N.F. Avd. 2, 36, No. 9. 



Notheiaceae 



Nizamuddin, M. and Womersley, H. B. S. (i960). Naturcj 187, 673. 



Sporochnales 



This is a small order characterized ordinarily by the aggregation 

 of the unilocular sporangia into swollen oval or elongate receptacles 

 that bear a cluster of hairs at their apex. Structurally they are 

 pseudo-parenchymatous with an intercalary, dome-shaped meri- 

 stem lying beneath the group of hairs that terminates each growing 

 branch. The gametophytes are microscopic plants which are 

 beUeved to reproduce oogamously. In view of this uncertainty the 

 life cycle obviously requires further study. 



The chief centre of distribution is in the southern hemisphere 

 where several species of Sporochnus occur together with the genera 

 Bellotia, Perithalia^ Encyothalia and Pseudosporochnus, which are 

 confined to this region. All the species tend to grow in deep water 

 and are only obtained in the castweed or else by dredging. 



Sporochnaceae : Sporochnus {sporo, offspring; chnus^ fine down). 

 Fig. 89 



The plants are moderately large and the branches are terminated 

 by a tuft of assimilatory hairs, each with a basal meristem. The 

 mature thaUus grows by means of a separate horizontal meristem 

 that lies beneath the tuft of assimilatory hairs. Young plants con- 

 sist of a simple erect thread anchored by rhizoids. The lower part 

 represents a pedicel which plays no further part in development. 

 The upper part forms the primary hair and the cell between the 

 upper and lower parts is the archi-meristem from which the adult 

 thallus is produced by longitudinal divisions in various planes. 

 Down-growing threads are produced which coalesce to give the 

 pseudo-parenchymatous body. The sporangia are borne laterally 



