385 



In a very straight leaf you will not find the veins separating widely apart ; just as 

 in a poplar leaf you would not get them straight. 



Then, notice their number in the square inch. These calculations are not 

 my own, nor do I know whence they were obtained. They are, however, as 

 follows :— 



Mesembryanthemum ... 



Yucca 



Iris ... 



Vine 



Hydrangea and Lilac 



The stem of the Cereus has ) , c nnn 



Ditto Stapelia f ^"'""" 



These numbers are very astonishing, and profoundly so when we reflect 

 upon the myriads there are in an entire tree or shrub. Still, there they are. Each 

 has its appointed mission in life. Each is useful for breathing. Moreover, they 

 work systematically, as is necessary from the very nature of the thing. Is the 

 weather very hot, these apertures close. They must not have too much moisture 

 extracted from them, or they would be exhausted. Moisture is essential to their 

 vitality. 



Observe now, the organ of breathing. There are two lips as shown clearly 

 enough in the diagrams I show you. These lips vary very much in shape as you 

 will see. Nor are they always simple. The horse-tail family (Equisetum) supply 

 compound forms ; not merely are there the ordinary two lips, but there are also 

 bars within them at right angles to them. 



There are some wonderful modifications in these breathing organs. Some 

 of them are delicate and need protection. They obtain it by means of beautifully 

 organised hairs which are to be found on certain plants. Whether the hair of the 

 common stinging nettle is used for this purpose or not I am not sure, but when the 

 leaves have hairs stellate in shape, these hairs have the power of elevation or de- 

 pression, according to the amount of moisture in the atmosphere, and consequently 

 are graduated in height so as to adapt the admission of moisture. 



In all these minute things then, we see design, wisdom, and excellence. 

 There is a rich field for investigation and study in every branch of science. The 

 more such fields are searched, the more they show how nothing could have come of 

 itself. 



I have only noticed the breathing organs as viewed from above. Sections 

 of leaves cut at right angles to the leaves, as generally seen by us, are most 

 interesting, and I have not touched upon them to-night. They furnish varieties 

 quite as numerous as those we have examined. Strange, too, it is, that whilst 

 phanerogams supply simple forms, they must yield the palm of honour as to 

 complicated beauty to the cryptogams. The lowly liver-wort will be found with 

 organisms far higher in the scale than any flowering plant owns. Thus again and 

 again do we detect the works of God in their glory. 



I have finished my paper, and have made it not very long, knowing that 

 others were to be read. I prefer to listen to them rather than hear myself, 



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