80 



processes have become more elongated, but they still have something in 

 their thickened extremities to remind us of the more primitive forms. 

 This is lost or modified in other members of the same family. 



Eecollecting that these axial processes are peduncles, we may dis- 

 cover them in Angiospermia, under various modifications. For instance, 

 in Pig. 6, we have a fruit which bears an external resemblance to a 

 cone, in consequence of the axial processes coming off in a somewhat 

 similar manner. This is the fruit of Freycinetia wibricata, one of the 

 Pandanaceae, or Screw Pines. Isolation and separation of parts pro- 

 ceeding still, we shall have the branched spadix of Palms as a resulting 

 form, the spathe perhaps standing for the involucre present in the com- 

 posite and umbelliferous plants. 



In the lowest forms mentioned the extreme receptacles are occasion- 

 ally outgrown; and where in the Pine we have the compound or male 

 cone, the axis is sometimes prolonged into a tuft of leaves. ]N"ow, in some 

 Arads we have this condition of things visible in a modified manner. 

 In Arum macalatum, for instance, the axis or spadix bears the female 

 and the male organs, next a few "nectaries," rudimentary leaves pro- 

 bably, and finally is prolonged into a cellular or fleshy club. 



Fig. 7 represents a vertical section of the caBnanthiuni of the Pig. 

 The peduncle has been said to be " excavated," the flowers being inside. 

 Might we not, however, rather regard a conceptacle of the Pucus as 

 a distant antetype of this inflorescence ? That also may properly be called 

 a caenanthium; for the " flowers" — i.e., the reproductive organs and 

 their filaments — abide together in community. Both are cavities con- 

 taining these, and opening to the air, each by a pore, be it large or 

 small. Around this opening are filaments, sometimes protruding in one 

 instance, and scales to represent them in the case of the Pig. These in 

 further developed forms receive the name of involucres. 



The direction of growth being coincident with the direction of 

 the axis, the tendency here is to push up the bottom of the cavity, and, 

 in fact, to turn the caenanthium inside out. In Dorstenia contrayerva 

 (Pig. 8) it will be noticed that this process has gone so far as to level 

 up the cavity, disparting its edges. In Fig. 9, the female capitulum of 

 Artocarpus incisa, the process has been fully completed. These three 

 are instances from plants closely allied. The capitulum of a Composite 

 shows the tendency described, changing the form of the peduncle extre- 

 mity as it flowers and ripens. In Pig. 10, for instance, the common Dande- 

 lion flower and peduncle extremity are shown. The peduncle is " exca- 

 vated" occasionally more deeply than what is seen in this hasty sketch ; 

 as it flowers and ripens, however, the centre rises into a conical form, 

 and the globular shape of the head of the perfectly ripened seed is well 

 known. On following this process attentively, it will be seen that the 

 scales around the mouth of the caenanthium have been displaced so as to 

 become the involucre of the capitulum. 



button of what represent the ovules in the loculi is explicable by what we see there. 

 Taken in this connexion, Schleiden's opposition to the theory of marginal placentation 

 receives support. 



