BO r A\ IC AL APPLICATIONS 



Fig. 7. Direct electron micrograph of scales of 

 Synura eichinulata; the structure at the base of the 

 spine is internal thickening, X 13,500. 



t ached to them. ChrysosphaereUa is rela- 

 tively uncommon compared with Mallo- 

 monas and Synura. 



Petersen and Hansen (27) have studied 

 some organisms associated with the surface 

 of the water as opposed to those types of 

 phyto-plankton which are free-swimming. 

 By means of a special technique they were 

 able to study single cells as they were situ- 

 ated on the water surface before drying. 



Marine algae have been studied in detail 

 by Parke, Manton and Clarke (28, 29) who 

 used direct examination and sections. These 

 authors are concerned mainly with the 

 micro-anatomy and taxonomy of Chryso- 

 chromulina. Their descriptions are extremely 

 detailed and informative. 



Manton and Clarke (30) have also given 

 a detailed and interesting description of the 

 spermatozoid of Fucus serratus. This inter- 

 esting organism is shown in Figure 9. Man- 

 ton and Clarke ascertained by comparing 

 UV micrographs and electron micrographs 

 that the body shrinks but does not alter its 

 shape in the electron microscope. The func- 

 tion of the fine hairs on either side of the 



front flagellum is not known. The proboscis, 

 which is highly mobile in the living state, is 

 a fimnel-shaped membrane surrounding the 

 front flagellum and attached to the body at 

 the base. When dry, the organ is flattened 

 and thirteen characteristic concentric thick- 

 enings can be seen. The study of the flagella 

 is particularly interesting since the morphol- 

 ogy can be compared with other flagella and 

 cilia. Electron micrographs of the disinte- 

 grated front flagellum show it to be com- 

 posed of eleven strands; in the rear flagel- 

 lum there are only nine. It is interesting to 

 note that fern cilia bear a close numerical 

 relationship (31) yet there is no phyletic or 



Fig. 8. Shadowed carbon replica of a complete 

 cell of Mallomonas coronata, X9000. (Courtesy of 

 Research) 



85 



