4 ILLUSTRATIONS OF INDIAN BOTANY. 



Mtjrtas is suffici- 



4 



the extravagant hypothesis of M. Fillette de Clermonf,, who fancies that it is due to the 

 cohesion of 3 ^oy/ers.^'—Lindley's Katural System of Botany, 



" This genus only differs from the other Myrtaceae by having two verticels of carpels 

 developed instead of one, and perhaps in a truly wild state the upper or adventitious one may 

 occasionally disappear. The inner series (or those at the bottom of the fruit) have their 

 placentae in the axis ; but the outer series, forced to the top of the fruit by the contraction of 

 the mouth of the tube of the calyx, having their placentae in the ovary at the back of the 

 inner carpels, exhibit them in the ripe fruit in a horizontal position on the upper surface of the 

 lower cells." — Arvott Encydop. Brit. Ed. 7, et Prod. Fl. peninsula I Pg. 327. 



Premising that the whole controversy turns on these questions, 1st, what is the true 

 structure of a Pomegranate ? and 2d, whether the difference between it and 

 ent to separate these genera as types of distinct orders ? 



I shall now proceed to examine these conflicting statements and endeavour to ascertain on 

 which side the balance preponderates and whether indeed, there is not room for an explanation 

 different from any of these yet proposed. 



Mr. Don's description of this fruit on the strength of which he first proposed to remove 

 this genus from Myrtaceae, the order with which it was previously associated, as a distinct 

 family appears to me most unphilosophical and altogether untenable. He, as I understand, 

 considers the fruit a one-celled receptacle the centre of which is filled with a spongy placenta, 

 round the surface of which there are a number of irregular cells occupied by clusters of ovules: 

 but he does not tell us how the central placenta got there neither does he account for the 

 ovules being attached to the parietes of the cell and not to the central placentae. 



His whole description in fact proves that it had been drawn up from inadequate examina- 

 tion and that he, at the very time he is accusing all authors of overlooking the real structure of 

 this fruit, totally misapprehends it himself, as we shall by and by see. 



DeCandolle gives a more correct description of it when he says that it consists of two 

 chambers, the under 3-celled, the upper from 5 to9-celled, with the placentas of the upper cells 

 reaching from the parietes to the centre while those of the lower division proceed irregularly 

 from the bottom of the fruit. He does not however assign this peculiar structure as his prin- 



estimation of minor importance. 



Myrtaceae 



Lindley conceives that there are two rows of carpels, three or four of which surround the 

 axis at the bottom, while the remainder surround these and occupying the upper part of the 

 fruit adhere to that part of the tube of the calyx. The placentas of these upper carpels he 

 conceives contract an irregular kind of adhesion with the back and front of ttieir cells. The 

 meaning of this is far from being clear to me, but if it means that he considers the placentas 

 of the upper as well as the lower row to proceed from the axis towards the circumference to 

 which last they contract accidental adhesions, then he takes an erroneous view and if the 

 examples quoted in illustration support this view, they are not in point as regards the structure 

 of Punka. 



Mr. Arnott like Lindley views the fruit as consisting of two rows of carpels, an outer and 

 inner, the former of which he thinks may be adventitious. To understand his theory we must 

 first suppose the tube of the calyx spread out as a flat surface and covered with two circles of 

 carpels, the inner next the axis and the outer occupying a larger circle beyond. That the 

 margin of the calyx then contracts so as to turn the outer series over the inner. According to 

 this supposition, the attachment or base of the placentas of the outer series should be in the 

 circumference and the apex in the centre, while that of the inner should be in the opposite 

 direction that is, have the base m the centre and the apex towards the circumference, an expla- 

 nation which is in accordance with what we find, except in so far as it does not account for the 

 horizontal partition between the two series, nor can I exactly understand on what ground we 

 are warranted in assummg that the outer series is adventitious and the result of cultivation as 

 It has every where been found so constant in all circumstances. But be that as it may this 

 theory certainly accounts for the crossing of the placentas in the two rows, which we so invari- 

 ably find, whether correctly or not cannot be determined until we get fruit with a single row of 

 carpels, which has not yet beea found. ^ ^ 



