ORGANIC 



'ear 



lFOtf9 



DEVELOPEMENT. 



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91 



Fig. 45. 



43. 



instances, the budding leaf-bud or flower proceeds from some one or 

 more of these cellules, which develope new powers of secretion 

 within themselves. These gemmating cellules go on developing 

 new cellules in lines, which frequently subdivide, until, in connexion 

 with the other attending conditions of growth, the bud forms and 

 developes, and the branch commences. 



88. The principal steps in the process, are exemplified in the 

 annexed figures. Figure 43, is a branch of 

 the natural size, of one of the coralline Algse, 

 taken from a clump, an inch and a half 

 high, and three or four inches through.* 

 The lower part is covered with minute dots 

 about TIU of an inch in diameter, which are 

 magnified in figure 44. Figure 45 represents 

 one of the longitudinal vessels of the inte- 

 rior, magnified one hundred and fifty diame- 

 ters, consisting of oblong cellules, a b, b c. 

 These cellules are 1-5^17? of an inch long. 

 From the summit of one (at b), a cellule pro- 

 ceeds laterally, which gives out two smaller 

 cellules, and these two others, and so on, and 

 the last connect with the sporules (not here 

 figured), which constitute the surface dots 

 alluded to : about five hundred sporules 

 being clustered in a single one of these dots. 

 These sporules are each about ufa* of an inch long. Thus we trace 



out the beginning of the germinant process in the first cell which 

 takes its outward course, and follow the progress of developement, till 

 prepared to form sporules at the extremity. 



With reference to the germinant process, in this case, it should be 

 remarked first, that it is not apparent within a third to half an inch 

 from the extremity of a branch, for sporules are formed only below 

 this distance : above this, the necessary nutriment is drawn off by 

 the growing summits, the younger parts of the coralline; as in 

 the zoophyte, germination does not take place, except where the parts 

 are beyond the influence of the reproductive force at the budding 

 apex. As the alga lengthens above, the sporidia form below succes- 

 sively, at nearly equal distances, in analogy with the branching of 

 zoophytes. 



* I have illustrated this point from dissections of a species of Liagora (L. rubriceps, D.), 

 obtained in the Feejees. 



