8 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 



inserted on the end of the pedicel at the bottom of the calyx, we would have the 

 rather absurd condition either that fibro-vascular bundles of two sets of leaves (petals and 

 stamens, or sepals and stamens) of different ages would be united in the organs them- 

 selves, or else that the stamens were borne on the other organs, just as in the first case, 

 only that the insertion would be a little farther down. If the attachment of the 

 stamens, petals and sepals is supposed to be at the place where the fibro-vascular bun- 

 dles separate, the axial portion would end at different heights {i. e., both at us and up, 

 plate ], fig. 3) and still a portion of the axis would be cup-ahaped. It is, therefore, best 

 to regard the whole of the cup axial. In this case the union of the fibro-vascular bun- 

 dles below the margin causes no difficulty as fibro-vascular bundles from leaves often 

 unite with other bundles in the stem. 



3. The axial origin of the cup is shown by the fact that, in Rosa and other genera, 

 it often bears bracts, indeed sometimes fully developed leaves with stipules even at a 

 place much higher than the insertion of the achenes, and both Masters and Henslow 

 state that supernumerary carpels are sometimes borne on its rim in the hawthorn. 



4. The real place of insertion of the sepals is at or at least near the brim of the cup, 

 just below the place of insertion of the petals. This is shown by the fact that in Rosa 

 the sepals, which in this genus are often leaf-like, sometimes bear at this point fully 

 developed stipules. The bractlets of the Potentilleae have usually been regarded as 

 representing the united stipules of two neighboring sepals. Another fact, indicating that 

 the point of insertion is at the place given above, is that in some species of Rosa and 

 other genera the sepals are deciduous at this point. Even in most of the Potentilleae this 

 place is also shown by a thickening of the tissue. This is most prominent in Horkelia 

 (Ivesia) BaiJeyi, Shockleyi, pygmaea and Comarella multifoliolata and sabulosa, where, 

 especially at the time when the fruit is ripe, there is a considerable swelling and a 

 decided break in the outline, the sepal making nearly a right angle with the axial 

 portion. 



The flower-axis can therefore be divided into two portions ; an inner of terminal 

 and an outer of lateral origin. The inner portion in the Potentilleae is typically more or 

 less conic or hemispheric, bearing the numerous pistils, which are generally inter- 

 posed with numerous longer or shorter bristles. For convenience I shall use in my de- 

 scriptions the word receptacle exclusively for this portion of the axis. In Ivesia, etc. 

 where the number of pistils is very small, the receptacle is very minute and in several 

 cases obsolete. In Fragaria, Dmhesnea and Comarum it much enlarges in fruit. In the 

 first genus it becomes fleshy and edible and constitutes the strawberry. 



The outer portion of the flower-axis is, as stated before, lateral and develops in 



