174 PLANT WORLD. 



Is rather too short a time. The seeds, however, Ross con- 

 tinues, germinate more readily in the soil loosened by pulling, 

 and this may be true enough, though I have found that the 

 seeds germinate in such numbers in unloosened soil that the 

 advantage on this account appears to have been inferred on 

 (I priori grounds. I have found as many as eight seedlings 

 on one square inch which had germinated on soil packed by 

 six months alternate rain and baking — chiefly baking, in 

 view of the low rainfall. They have been seen to germinate 

 in a soil the surface of which was hardened to a crust by 

 salts. The question, therefore, would appear to be one which 

 can be answered better after a considerable study of an 

 area of guayule which has been treated by the method of 

 pulling. Observation leads one to believe that shade is a 

 more potent factor. More seedlings are usually to be found 

 in the shade of a large guayule bush than anywhere else, 

 and very often one finds a half-dozen plantlets from one to 

 several years old ^'ery near to the presumable mother plant. 

 This brings us to the question of the relative importance of 

 seed in reproduction, which, according to Ross is minor. The 

 actual count of seedlings in the field to the mind of the 

 reviewer clearly negatives the view expresseci by the phrase 

 "apparently weak reproduction by seed." In some areas 

 to be sure, there is a weak reproduction by seed, but the 

 relative number of large and small plants (seedlings) varies 

 in all ratios, and, l)y count, has been found to be from 300 

 plants of less then 0.12 of a pound to 5 such, nil seedlings. 

 As I have elsewhere shown, a weak germination, or at least 

 subsequent growth in the resultant seedlings, occurs on 

 rather steep slopes of a certain character, where is to be 

 found a shallow soil, but here a vegetative method, by means 

 of new shoots from the roots of plants /// situ, compensates 

 for this. 1 ake it by and large, a close study of Held con- 

 ditions leads inevitably to the view that seeding plays a most 

 important part in the reproduction of the plant. Ross in 

 this connection states that many attempts have been made at 



