572 MANUAL OF POISONOUS PLANTS 



found in screenings and fed in large quantities to cattle. As far as the writer 

 knows, there are no cases of poisoning recorded from eating the screenings of 

 this seed. The substance vicin CgH^^NgOg has been found in the seeds of 

 this species. Convincin Cj^H^jNgOg+HjO also occurs in this species and in 

 V. Paba. Citric acid CgHgO^+H^O is found in V. sativa. 



19. Lathyrus (Tourn.) L. Vetchling. Everlasting Pea 



Mostly perennial, herbaceous vines although there are, a few erect herbs, 

 generally smooth, with pinnate, usually tendril-bearing leaves ; flowers in racemes 

 or solitary; calyx oblique or gibbous at the base, upper teeth sometimes shorter 

 than the lower; corolla larger than that of Vicia, wings adhering to keel; style 

 dilated and rather flat above, hairy along side next to free stamen; stamens 

 10 (9 and 1, or monadelphous below); ovules numerous; pod flat, sometimes 

 terete, 2-valved, continuous between the seeds, dehiscent. 



About 100 species are distributed throughout North America and a few 

 others are found in South America and the mountains of tropical Africa. One 

 species, L. sylvestris, is considered poisonous, in its native home in the Car- 

 pathian Mountains. It contains certain alkaloids which, by the process of cul- 

 tivation have become eliminated so that in many localities at the present time 

 it is considered a good forage plant and is relished by horses. In the western 

 United States, the prairie vetchlings L. ornatus and L. polymorphus, and the 

 marsh vetchling L. palustris are considered valuable forage plants, the latter 

 forming a very important part of the hay and adding materially to its feeding 

 value. L. venosus and L. ochroleucus occurring in similar localities are much 

 less valuable. A form of intoxication, known as Lathryism, is said to be caused 

 by different species of Lathyrus. 



In Dr. Wilson's "American Text-Book of Therapeutics," Victor C. Vaughan 

 translates the following account of Lathyrism from Robert's work "Intoxika- 

 tionen :" 



By Lathyrism we mean an intoxication that was known to the contemporaries of 

 Hippocrates, and which was caused by the seeds of at least three species of vetch, Lathyrus 

 hirsutus, the red vetch, Lathyrus saiivus, the German vetch, and Lathyrus Clymenutn, 

 the Spanish vetch. In Spain, France, Italy, and in certain parts of Africa and India there 

 have repeatedly appeared, from the eating of the seed of the vetch, epidemics of a dis- 

 ease that especially affects males and which induces a transverse myelitis with motor 

 and sensory paraplegia. The paralytic symptoms gradually disappear, but there remains 

 spastic tubes with heightened tendon-reflexes attributed by Proust to secondary degeneration 

 of the lateral columns, while Striimpell considers the case a typical spinal paralysis. How- 

 ever, the symptoms may wholly disappear and recovery be apparently complete. Men and 

 animals, especially horses, are affected in the same manner, Duvernoy described the dis- 

 ease in 1770; Doir saw it follow the eating of vetch-bread in 1785; Despranches observed 

 it in France in 1829, and Pellicotti in the Abbruzzo mountains in 1847. Reports of the 

 disease were made by Irving, in India, in 1861 and 1869, and by Bourlier in Africa in 

 1882. In 1883, Marie published in Le Progres Medical a review of the literature of the 



subject and more recently Schuchardt has done the same Hogs are killed 



quickly by the vetch. Horses suffer from paralysis of the recurrent laryngeal nerve, 

 necessitating tracheotomy. More chronic poisoning causes paralysis of the posterior ex- 

 tremities, and death. Mericourt believes the disease beri-beri is due to a similar intox- 

 ication, but this is denied by Marie and others. In horses there is atrophy of the muscles 

 of the larynx, especially of the cricoarytenoideus posticus and lateralis, also of the 

 thyroarytenoideus. The left recurrent laryngeal nerve is much wasted. Microscopic exam- 

 ination shows the muscle greatly atrophied, without striation, and undergoing fatty 

 degeneration. In the central nervous system one iinds atrophy of the ganglion-cells >n 

 the vagus center and of the multipolar ganglion-cells in the anterior horns of the cord. 



