460 Mr. B. Clarke on Relative Position; 



the posterior side of the ovary, and so much so as to show clearly 

 that the carpel is anterior. 



Ulmace^e. In Ulmus montana and Celtis orientalis the ovary 

 consists of two carpels, which is shown in the latter instance by 

 the stigmas remaining only two when the ovary becomes bilocular ; 

 and the attachment of the pendulous ovule to the more promi- 

 nent of the two ribs of the ovary (which, as in Moms, are oppo- 

 site the stigmas) may therefore be regarded as an indication of 

 the position of the placenta, and consequently of the fertile car- 

 pel. This is also the structure of Elatostemma among Urticacese. 

 (PI. XV. figs. 21 & 22.) 



Casuarine^. In Casuarina the attachment of the seed rather 

 above the middle of the posterior angle of the cell is relied on as 

 an evidence of the position of the carpel. The ovary has the 

 same structure as that of Ulmus and Morus, as the stigmas are 

 two, and the posterior side with which the seed is connected is 

 much thickened (PI. XV. fig. 25). The fertile carpel is anterior 

 with the same regularity as the scale-like ovary of Pinus ; the 

 position of the stamen is also uniform, and has all the appearance 

 of being anterior. 



Myricace^e. The ovary of Myrica quercifolia bears evidences 

 of being compound, consisting of two or three carpels united by 

 their margins as in Lacistemacese, and Myrica may thus connect 

 that family with Urticacese and Cupuliferse ; the position of the 

 carpels when two (the usual number) nearly agreeing with those 

 of Quereus when two-celled. 



CupuLiFER^. In Cupuliferse the position of the carpels when 

 two is variable, in Corylus Avellana all being anterior and pos- 

 terior, the axils being two-flowered from the central bud remain- 

 ing undeveloped ; but in Quereus Robur when dicarpous nearly 

 all right and left, and therefore the single carpel could not be in 

 the latter case always anterior as in Casuarina. But the instance 

 of Fagus sylvatica perhaps shows the position the single carpel 

 would occupy in that genus ; the inflorescence consists of two 

 flowers terminating a branch, the central terminal bud of which 

 is abortive, and the two flowers are thus opposite each other. 

 Each ovary consists of three carpels, two of them lateral and one 

 anterior; of these the anterior is the larger, and the anterior 

 cell is I believe more frequently fertile than the others, as also in 

 Castanea vulgaris. Possibly there is an analogy between this 

 enlargement and that of the anterior carpel of Schweiggeria. 



BETULACEiE. Betula is remarkable in having a three-flowered 

 axil, the carpels in the central ovary being I'ight and left, while 

 those of the two lateral are anterior and posterior (the central 

 flower being considered as axis to the lateral) ; but as the ovary 



