44 Mr Don on the irritability of the Stigma in Pinus Larix. 



ovulum. When impregnation has taken place, the sides of the 

 stigma again expand, and soon after wither. In this state, the 

 stigma is seen filled with the empty cells of pollen. If a branch 

 with female catkins is separated from the tree before impregna- 

 tion has taken place, it is surprising how long the stigmata will 

 remain expanded and in a perfect state. This circumstance has 

 been also remarked in the female organs of other plants. That 

 the amentum of Finns is nothing more than a modified branch, 

 is well exemplified in the larch, where a comparison between an 

 expanding bud and the female catkin is at once convincing. 

 The bracteae, which in the larch are persistent, being regarded 

 as altered leaves, the flowers are, therefore, truly axillary, and 

 their situation may be compared to those of Hippwis. The 

 fleshy scales, which afterwards compose the cone, are analogous 

 to the nectarium of Salix, &c. ; and one of their uses, namely, 

 the nourishing the early stage of the ovarium, as the albumen 

 does the embryo, is precisely similar. The ovaria at first are 

 firmly attached to the upper surface of the scales ; but on their 

 increasing in size, they by degrees lose the connection, till at 

 length, in the ripe state, they become perfectly free. These 

 scales, in the early state, are fleshy and orbicular, composed of 

 a cellular substance, having neither veins nor nerves traversing 

 them ; their upper side is convex, and underneath flat, with an 

 acute, slightly fringed margin ; the whole surface is pruinose : 

 in the young state succulent, and gradually increasing in size, 

 they finally constitute the cone, becoming then dry, coriaceous, 

 or woody. In this state, from their arrangement and structure, 

 they admirably serve to protect the seeds from the destructive 

 effects of the severe weather to which in winter they would 

 otherwise become exposed ; and we cannot but admire the wise 

 provision of Nature in this instance, which has given to these 

 natives of cold regions the means of protecting their seeds 

 through the winter, until finally matured in the warm weather 

 of the following spring. In judging of the origin and analogies 

 of the stamina in Conifera^, instead of looking for the resem- 

 blance in the leaves, we must begin by comparing them with 

 the bracteae of the female catkin, which we have already shewn 

 to be modified leaves ; and it therefore follows, as a deduction, 

 that they are both modifications of the same organ, namely of 

 the leaf. 



