1880.] 



MICROSCOPICAL JOURNAL. 



195 



attracting to ants and flies. Further, 

 there is on the inner surface of the 

 hood and mouth, a formidable array 

 of comparatively long pike-pointed 

 spines, all pointing backward and 

 downward. These grade off into 

 shorter, more blunt, but still exceed- 

 ingly sharp-pointed spines, which 

 overlap each other like tiles on the 

 roof of a house. This kind of 

 coating lines the tube for a third of 

 the way down, the spines growing 

 Uner until at last they grade off into 

 regular hairs which line all the lower 

 part of the tube ; spines and hairs all 

 pointing downward. An insect at- 

 tempting to retrace its steps after 

 its ambrosial feast, would iind 

 nothing which it could penetrate or 

 grasp with the booklets of its feet ; 

 and the wetness of the spines, from 

 the constantly overflowing glands, 

 would probably prevent it from 

 making use of any other device that 

 insects may have for climbing glazed 

 surfaces. As a matter of fact no 

 creature comes out of that prison 

 house, unless it be with the single 

 exception of one cunning spider, 

 which in some way finds a safe and 

 rich retreat under the hood of its 

 great vegetable rival. 



The bodies of the captured prey 

 fall into the fluid in the tube and are 

 macerated or decomposed, but with- 

 out any signs of putrescence. 

 Therefore the plant must at once 

 absorb the animal matter, for other- 

 wise this would cause the infusorial 

 life, which is called putrefaction. 



In order to show the internal 

 structure of the pitcher plant leaf, it 

 will be necessary to separate the 

 cuticle which bears the spines and 

 glands from the rest of the leaf. To 

 do this, pieces cut from the leaf, and 

 preferably those showing the transi- 

 tion from one kind of spines into 

 another, after being soaked in water, 

 may be put into common nitric acid, 

 and this brought up to the boiling 



j)oint over an alcohol lamp. They 

 should then be immediately washed 

 in several waters, when it will prob- 

 ably be found that the cuticle, both 

 the inner and the outer, has already 

 separated from the parenchyma. 

 The specimens will need no further 

 bleaching, and may be stained either 

 in eosin, dissolved in water, or in 

 anilin blue in alcohol. As there is 

 only one kind of tissue to be stained, 

 it will be im jjossible to get more than 

 one color in them. They should be 

 mounted, or kept in water very 

 slightly acidulated with carbolic 

 acid. 



I cannot but regard the pitcher 

 plant as the most highly developed, 

 and the most specialized in its or- 

 ganization of any of the insectivor- 

 ous plants. It differs more widely 

 from ordinary vegetation, and has 

 more special and adapted contrivan- 

 ces about it, than any of the others. 

 Now, as I believe that the truth of 

 the modern evolutionary theory will 

 be eventually brought to the test 

 by well-studied monographs, made 

 by microscopists, on some such 

 highly differentiated organic struc- 

 tures as this pitcher plant, I do 

 not deem it a disgression to present 

 here briefly some inferences which 

 seem to me to arise from the devel- 

 opmental history of this particular 

 plant. Of course, if the pitcher plant 

 was developed from other and ordi- 

 nary plants, it had at one time the 

 simple plain leaves of common herbs. 

 It must have early commenced in 

 some way, to appropriate insect food 

 on these leaves, because every essen- 

 tial change was for the bettenment of 

 the plant in this respect. The stem 

 of the leaves soon began to put out 

 flanges or wings on each side — the 

 phyllodia of the botanists, which are 

 not uncommon among plants. And 

 these outspread wings must have as- 

 sisted in the absorption of insect food 

 that was washed down among them. 



