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NATURE STUDY IN SCHOOLS. 



( See fig. 138, B. ) Here the polyps grow upward and from their sides start 

 buds which form polyps that may develop into blanches. Division takes 

 place in many species. When the polyp has attained a certain size it di- 

 vides, and this division is indicated by the skeleton. See fig. 138, C, occe- 

 lated coral, and fig. 137, B, tooth coral, both of which show polyp cells 

 where division has occurred. Eggs are deposited much as in the anemonie. 



Fig. 139. 



Fig. 140. 



Brain Coral. 



Propeller Coral. 



Fobms of Corals. 



The corals may be divided into two groups, according to habit, reef 

 building and lagoon inhabiting. 



The reef building species in our Atlantic waters are, the plate, fig. 138 

 A, 'the brain, fig. 139, the head and the fan coral. Among the lagoon in- 

 habiting may be found the branching, fig. 138, B, the occelated, fig. 138, C, 

 the propeller, fig. 140, the large star, tooth, lancet, fig. 137 A, B, C, the globe, 

 forking and rolling. See fig. 134, A, B, C and D. 



[Note. Systematic Zoology for Teachers will appear in book form at a 

 future date and will be sold to subscribers to Nature Study in Schools at a 

 discount. ] 



