262 Dr. R. Wight on the Fruit of the 



that by losing the general character of dissepiments they 

 might ahnost be said to disappear ; and thus at first sight a 

 pepo would be said to be, and has been so described, a one- 

 celled, fleshy, indehiscent fruit, with parietal placentae, that 

 send out sometimes false dissepiments towards the axis, as the 

 cucumber and gourd." 



This view, therefore, is essentially different from Dr. Lind- 

 ley's ; for, according to Arnott, the placentae are virtually 

 central, not parietal ; the only difference between a pepo and 

 an apple being, according to him, that the place ntiferous 

 margins of the carpellary leaf are introflexed, and extend out- 

 wards nearly to the parietes of the fruit, in place of remain- 

 ing in the axis. Lindley, on the other hand, views a pepo 

 simply as a one-celled fruit with parietal placentae, the cavity 

 being occasionally divided into spurious cells by projections 

 of the placentae. Neither are altogether consonant with ap- 

 pearances, though that of Arnott appears the most so ; but 

 both, in common with all others that have yet been promul- 

 gated, are incorrect both as to theory and fact. 



While our ideas of the structure of the most essential or- 

 gan of the plant, with reference to natural affinities, are thus 

 vague, can it be matter of surprise that we are unable to trace 

 its relations, and determine its affinities in the system of 

 plants ? 



What then is a peponida ? I have said above that it is 

 neither a one-celled fruit with parietal placentae, nor a three- 

 celled one with introflexed central placentae. But before I 

 can say what it is, and point out the difference between it and 

 a fruit of the usual construction, it is necessary to state what 

 the usual structure is. This I shall do by means of a short 

 extract from Lindley's * Key to Structural Botany.' 



" 354. A Carpel is formed by a folded leaf, the upper sur- 

 face of which is turned inwards, the lower outwards ; and the 

 margins of which develope one or a greater number of buds, 

 which are the ovules. 



"355. When the carpels are stalked, they are said to be 

 seated upon a thecaphore, or gynojifiore; Ex. Cleome,PassiJlora. 

 Their stalk is analogous to the petiole of a leaf. 



"355 a. When the carpels are all distinct, or are separable 

 with facility, they are apocarpous ; when they all grow into a 

 solid body, which cannot be separated into its constituent 

 parts, they are syncarpous. 



"356. The ovary is the lamina of the leaf. 



"357- The style is an elongation of the midrib (174.), 



"358. The stigma is the denuded, secreting, humid apex of 

 fhc midrib. 



