7O A NEW ZEALAND NATURALIST'S CALENDAR. 



contained some little animal. If quite ripe these pods will 

 crack into four ribbon-like valves and by the rapidity with 

 which they twist will throw out their seeds. All the 

 balsams have this property, and on account of it the genus 

 has received the suggestive technical name of Impatiens. 

 The yellow balsam of the Welsh and Northumbrian hills 

 in Britain is called noli me tangere "let no one touch 

 me," from this irritability of the seed pods. In Britain 

 two other species have been introduced and are rapidly 

 spreading, and it is noticeable that the kind I refer to as 

 found here is inclined to be a weed in all the gardens in 

 which it occurs. 



The only other plant common in our gardens which 

 throws its seeds away from it is the Oxalis. I do not 

 profess to know whether this is the trae shamrock or not, 

 but the plant often goes by that name. In this it is not 

 the seed-pod which bursts, but a peculiar fleshy network 

 or skin in which the seed is enveloped, and which ruptures 

 with force sufficient to throw its contents some feet away. 

 The most curious example of this property possessed by 

 some plants of scattering their own seeds was met with by 

 me some years ago in the Melbourne Botanical Gardens. 

 Seeing a plant with gourd-like fruit, I touched one with 

 the point of my stick and was at once saluted with a slight 

 report and a volley of pulp and seeds. The plant was the 

 curious squirting cucumber of Southern Europe. It might 

 be asked, If such devices are so valuable to the plants 

 possessing them in enabling them to disperse their seeds, 

 how are we to explain the case of plants, like chickweed 

 and other common weeds of cultivation, which merely 

 allow their seeds to fall out on the ground round and 

 under them? It will generally be found in such cases 

 that the plants depend for their success in the struggle for 

 existence on their ability to crowd out or to smother their 

 opponents, and they are usually furnished with great 

 numbers of rapidly germinating and maturing seeds. It 

 must further be borne in mind that a device which may 

 be advantageous in one plant or group of plants may be 

 apparently superseded by some different device in other 



