88 Mr. Burnett on the Development 



ence, organs of nutrition and reproduction ; and although the 

 intermediate or accessary organ of extension is not so essential 

 as these to mere existence, it will be found, that upon the 

 relative development of this accessary part depends in a great 

 measure the relative development and distinction of the other 

 systems. 



But to proceed : Let the intermediate stock or caudex, 

 i. e., the organ of extension, be that from which the examina- 

 tion of the vegetable may commence. In its simplest forms, 

 as in the protophytic algae, and in some of the lower fungi, as 

 reticularia, sphseria, &c,, it remains latent, or but partially 

 evolved, so that the nutrient and generant are equally present 

 in every part, and no distinction of organs for different func- 

 tions is perceived ; gradually, however, in the rising scale of 

 organization, the stock or caudex becomes extended, and as 

 gradually the nutrient and generant become located in distinct 

 and different parts, the nutrient chiefly in that which ordina- 

 rily pursues a downward course, hence called the descending 

 caudex [caudex descendens] or caudescens ; the generant, 

 principally, [though, like the nutrient, not exclusively,] in that 

 which quits the earth, and, rising upwards, seeks the air, hence 

 called the ascending caudex [caudex ascendens] or caudascens. 

 The whole of the organ of extension abstractedly considered, 

 without reference to the nutrient and the generant, is the stirps 

 or stock, i. e., the caudex ; the central portion is the stock-heart, 

 and, according as it has been considered either the crown of 

 the root, or the seat of the stem, or the boundary between 

 them both, it has been called indifferently corona, sedes, vel 

 limes, and, sometimes, from its shape, collum or coarctura : 

 the caudescens is the stake of the root, and the caudascens 

 the stalk of the herb ; the rootstake, when in union with its 

 absorbents or radicles, i. e., with the chief organs of nutrition, 

 becomes a true and proper root, as the stalk, when bearing the 

 generant, i. e., the reproductive organs, viz. gems and seeds, 

 becomes the stem or herb. 



Such being the physiology of segregational development, 

 it cannot seem surprising that the functions of plants are but 

 relatively distinct ; that many instances occur in which they 

 are intimately blended, and in which, without much care, both 



