110 Trans. Acad. Sci. of St. Louis. 



cattle, as noted by Sargent (221). Cattle feed on the pods 

 when forage is scarce. Some farmers of Texas have pro- 

 posed to plant the tree extensivelj so that it may be used for 

 this purpose during the dry season. Its distribution in Texas 

 has, no doubt, been largely brought about by cattle. The 

 excrement forms a most suitable nidus for the germination of 

 the seed. Dr. A. P. Anderson, of South Carolina, informs 

 me that the seed of Sesbania vesicaria passes through the 

 digestive tract uninjured. 



The wide distribution of Lespedeza striata over the South- 

 ern States is due, according to Mohr (184), to the excrement 

 of herbivorous animals. I am reliably informed that the 

 seeds of Cassia Chamaecrista are disseminated by sheep in 

 Southwestern Iowa. The disseminators in this instance suf- 

 fered some inconvenience because of the cathartic action of 

 the seed. Grisebach (78) and Morris (184a) have shown 

 that the distribution of Pilhecolohium in the West Indies is due 

 to herbivorous animals. Morris states that Acacia arabica 

 is fed to D-eese to hasten its germination. The Ceratonia 

 siliqua is also disseminated by animals, the hard seed readily 

 passing the digestive tract uninjured (Huth 119). The at- 

 tractive seeds of Adenanthev a pavonia L., Fongatnia Coral- 

 laria Miq., and Abrus precatorius are disseminated by birds. 

 Buchwald (35) gives a number of additional cases of African 

 seeds disseminated by birds. Dinter (58) states that oxen 

 are very fond of Acacia giraffae, and the result is that thou- 

 sands of young plants spring up in gardens where the manure 

 is scattered. From an ecological standpoint the Malpighian 

 cells certainly have a very important function to perform. 



Has the Malpighian layer any other function than that of 

 protection? Mattirolo and Buscalioni (174. 171) state that 

 water enters by way of the micropyle and replaces the air, 

 causing the testa to expand. In some further experi- 

 ments (175) these writers affirm that when sections are 

 treated with coloring matter it enters through the pore- 

 canals into the underlying cells and tissues of the plant. 

 The light line does not prevent water from entering, but its 

 outward flow is checked. The light line checks transpiration 

 during dry weather. The outer part of the Malpighian cells be- 



