90 TOILERS IN THE SEA. 



becoming filaments, and the adjacent filaments ulti- 

 mately anastomosing, or rather coalescing, as soon as 

 they come into contact. The spines are never tubular, 

 the appearance of tubularity in the spines of some 

 genera being due to the existence of short longitu- 

 dinal furrows and buttresses on their inner aspect, 

 where generally may be seen an aperture around a 

 portion of the margin of which the base of the spine 

 has taken its rise. When loops or festoons occur the 

 process is still the same, as these may be seen in every 

 stage of growth, from the first projection of a minute 

 filament to the stage at which the coalescence would 

 have become complete had the protecting and forma- 

 tive living sarcode been left to fulfil its office. In 

 short, the process may be familiarly likened to that 

 by which the glass-worker extends his plastic and 

 half molten material from point to point, when manu- 

 facturing a miniature basket work. Of course the 

 thickening of each portion is by subsequent deposit 

 around the original thread." 1 



The number of genera and species of Radiolaria 

 was increased enormously by the results of the Chal- 

 lenger expedition. The total number described by 

 Haeckel, in his " Report," was 739 genera, and 4,318 

 species, of these 3,508 were new, as against 810 pre- 



1 Dr. Wallich, in Quart. Journ. Micro. Science, v. p. 82. 



