500 



SCIENCE. 



[N. S. Vol. III. No. 66. 



much of the energy commonly expended in 

 reproduction, and thereby approach the 

 plane occupied by the higher animals, with 

 man at their head, among which progeny 

 are reduced in number and improved in the 

 perfection of their adjustment to environ- 

 ment — the plane of solidarity founded on 

 conscious or unconscious altruism, whose 

 occupants, sometimes erroneously classed 

 as sexually degenerate, are the socially re- 

 generate of the earth in that they are fitted 

 to the fulness of life in all its forms. 



During the earlier expedition it was 

 found that the plants of Papagueria, " how- 

 soever divergent phylogenically, are not- 

 ably convergent in a certain group of char- 

 acters, including leaflessness, waxiness 

 hairiness, thorniness, and greenness";* dur- 

 ing the later trip these inferences were 

 verified and corroborated, and it was also 

 observed that still other features are com- 

 mon among genetically diverse plants. 

 Thus, there is a series of trees and woody 

 shrubs, including a half dozen desert forms 

 known as torote, torotito, etc. (not yet 

 identified), which are characterized by 

 swollen trunks and squat forms, in which 

 the woody tissue is pulpy in texture and 

 saturated with watery or slightly viscid sap. 

 When trunk or branch is wounded the sap 

 exudes and quickly heals the wound, either 

 by coating it with lacquer or encrusting it 

 with gum ; and when the plant dies the sap 

 escapes and the wood shrinks and gapes 

 widely, even before the bark decays, so 

 that decomposition is rapid and the dead 

 crop quickly makes way for the rising gen- 

 eration. This pulpiness of stem among 

 ligneous plants is like unto the pulpiness of 

 the cactus and agave, which appears to be 

 a device for the storage of water ; and while 

 a few of the desert trees (ironwood, cat- 

 claw and paloblanca) are characterized by 

 firm woody tissue, most of the arboreal 

 forms consist largely of water-storing tis- 

 *0p. cit., page 362. 



sue, which may be inferred to represent 

 phylogenic adjustment to an arid environ- 

 ment. Commonly these water-filled trees, 

 with certain lesser shrubs abounding in vis- 

 cid juices and gum, are acrid, astringent or 

 ill-flavored, and some are alleged to be pois- 

 onous ; others are pungent or noisome in 

 odor (e. g. the yellowtorote has a penetrating 

 cedar-like odor which is highly offensive to 

 many animals). Associated with these 

 sappy and juicy plants there is a variety of 

 spicy shrubs which in the settled districts are 

 used as condiments and even as substitutes 

 for salt in curing meat. Many of these 

 plants are used medicinally; after describing 

 in detail the virtues of thirty-six medicinal 

 plants, the anonymous author of the ' Rudo 

 Ensayo ' (Sonera's classic, written in 1763), 

 adds, " Among the great variety of plauts 

 found at every step there is hardly one that 

 has not healing qualities ;" * and there 

 is reason to anticipate substantial additions 

 to the pharmacopoea as the flora is studied 

 systematically. Now it is noteworthy that 

 the high-flavored and strong-odored plants 

 are without thorns or other mechanical pro- 

 tective appurtenances ; and, in view of all 

 the relations, it seems almost necessary to 

 infer that the flavors and odors are protec- 

 tive and the product of phylogenic develop- 

 ment under the local conditions. If tliis be 

 so, it would appear that the mechanical and 

 chemical devices for individual protection 

 are related reciprocally ; and this corollary 

 finds direct support in the characteristics of 

 the cacti, for the juice of the scant-thorned 

 cina is offensive to herbivores, while the 

 well-thorned choUa and nopal are eaten by 

 stock when the thorns are burned off by the 

 vaqueros, and the bisnaga, thorniest of 

 known plants, yields a nearly pure water 

 which has saved the lives of scores of ex- 

 plorers (indeed the work of the last expedi- 

 tion was greatly facilitated by the supplies 



*Am. Catb. Hist. Soc, of Philadelphia, Vol. V., 

 1894, p. 164. 



