SPERMATOPHYTA— ORCHIDACEAE 395 



Dr. MacDougal * made a personal experiment with a mature specimen of 

 C. hirsutum on which there were newly formed seed pods. This plant was 

 broken oflfnear the base of the stem and the leaves brushed lightly over the 

 arm. 



A slight tingling sensation was felt at the time, and, fourteen hours later, the arm 

 was greatly swollen from the shoulder to the finger tips. The portion covered by the 

 plant — covering an area of 50 sq. cm. — was violently inflamed and clovered wilth 

 macules, accompanied by the usual symptoms of dermatitis and constitutional disturbances. 

 By treatment of the most approved kind, the arm was reduced to its normal size in ten 

 days, but the effects were perceptible a month later. 



Nestler discovered that the secretion contained in these hairs was a fatty 

 acid readily soluble in alcohol and benzol and producing a mildly acid reaction. 

 He also states that his results with C. pubescens were negative but that with 

 C. spectabile (C. hirsutum Mill.) he secured positive results, producing a derma- 

 titis, the action, however, not being so pronounced as that reported by Mac- 

 Dougal. He also found that, as stated above, the maximum poisonous effect 

 was during the formation of seed capsules and that the poison was in the 

 hairs of the plant as is the case in the Primrose. Nestler did not succeed in 

 producing dermatitis with C. parviflorum, C. acaule, C. macranthum, C. monta- 

 num, or Calceolus. As some of these species produce an abundance of 

 raphides in the stem, it is evident that dermatitis is not caused by these crystals, 

 but rather by a substance found in the stem. Dr.MacDougal suggests that 

 the raphides may serve the plant as a protection from animals. 



Nestler also asserts that the Cypripedium may contain an additional sub- 

 stance myelin which Senf has found in Ginkgo seed, and Nestler i himself ob- 

 served in the fruit of Capsicum annuum. It is not a cardol. 



From the root of Cypripedium a substance is obtained which is sometimes 

 administered to children as a substitute for opium. It contains a bitter glu- 

 cosidal principle. 



Class, DICOTYLEDONEAE 



Stem usually oxogenous with pith, wood and bark (endogenous in a few 

 plants) ; the woods traversed by medullary rays ; leaves usually pinnately or 

 palmately netted-veined ; embryo of the seed with 2 cotyledons or occasionally 1 ; 

 parts of the flower usually in S's, rarely in 3's or 6's. 



Archichlamydeae 



Petals separate and distinct from each other or wanting. Includes many 

 plants classed as Apetalae and Polypetalae. In some orders, as Leguminosae, 

 the lower petals are more or less united and joined at the base. 



VERTICILLATAE 



Contains a single family Casuarinaceae of 20 species, mostly Australian, 

 with monoecious flowers. The Casuarina equisetifolia of the tropical Old World 

 furnishes a hard wood known as iron wood and in Egypt the trees are used as 

 a shelter belt for bananas. 



* Minn. Bot. Studies. 1894:32-36. . , , „ ■■ i u. 



1 Das Sekret der Drusenhaare der gattung Cypripedium mit besonderer Berucksichtgung 

 seiner hautreizenden Wirkung. Nestler. Ber. der Dent. Bot. Gesell 25:554-567. 



