92 THE PHENOMENON O 



We now come to the transitions within the flower 

 itself. The transition from the calyx to the corolla cor- 

 responds^ to that from the cataphyllary to the euphyilary 

 formation, and takes place like this, without any, or with 

 an insignificant retrogression of the leaf-formation, on 

 which account no suppression occurs between these two 

 formations. We have above seen, in many cases, an 

 increase of the leaf- formation within the calyx, and re- 

 cognised in this the expression of the renewed impulse 

 received in the first half of the flower ; the contrary case, 

 a decrease of size following the order of succession of the 

 sepals, expressing an indentation in the line of impulse 

 ascending to the corolla, is a rare phenomenon, and is 

 only represented by faint indications. Thus in the 

 Gentian ce, Gerania, Nicotiana, even in the Roses and 

 Brambles, the inner sepals are somewhat shorter than the 

 outer. Of all cases of this kind, the calyx of Acanthus 

 exhibits the most striking character, which, however, 

 from the irregularity of the whole flower, cannot be 

 explained simply in this way. It is composed of four 

 pieces, an upper, broadest and longest (the second sepal); 

 a lower, somewhat narrower and shorter, which has two 

 points (it is formed from the confluence of the first and 

 third sepals) ; finally, two lateral, which stand further 

 inwards, and are much shorter than the upper and lower 

 pieces.* These little lateral sepals are the fourth and 

 fifth, consequently the last two leaves of the calyx. The 

 calyx is preceded by two very narrow linear bracteoles, 

 which are about half as long as the calyx j a broader and 

 longer bract, having sharply-toothed borders, bears the 

 flower in its axil. Here, therefore, we see a descent from 

 the bract to the bracteoles, an ascent from the two 

 bracteoles to the outer sepals, and another descent from 

 these to the two inner, and finally, from these to the 

 corolla a fresh ascent of the leaf- formation. 



That which is found only in rare and faint indications 



* The two lateral pieces are If to 2 lines long, the lower about 15 lines, 

 the upper 17 lines. 



