386 EXPERIMENT STATION RECORD. [Vol.38 



invade the lungs as well as other organs beyond the alimentary tract and can 

 cause a serious or even fatal prfumonia indicates that these parasites are 

 endowed with greater capacity for harm than has heretofore been supposed. 



"Age is a highly important factor in determining susceptibility to infection 

 with Ascaris, and susceptibility to infection greatly decreases as the host 

 animal becomes older. This, of course, Is in harmony with the well-known fact 

 that it is particularly children and young pigs among which infestation with 

 Ascaris is common, and that Ascaris is relatively of rare occurrence in adult 

 human beings and in old hogs." 



In a footnote the authors call attention to the fact that later experiments 

 with guinea pigs have shown that they also may be infected by feeding Ascaris 

 eggs, and that the migration of the larvae in this animal so far as observed 

 is identical with that noted by Stewart in rats and mice. All of six guinea 

 pigs infected died from pneumonia seven and eight days after feeding with 

 Ascaris eggs, the lungs being found heavily infested with Ascaris larvae. 



RURAL ENGINEERING. 



The waters of the Rio Grande, W. P. Headden {Colorado Sta. Bui. 230 

 {1911), pp. 3-62). — This report states that the Rio Grande flows for about 60 

 miles through the San Luis Valley without any considerable change in the 

 character of its waters, the flow diminishing rather than increasing. " There 

 are only a few streams having a visible discharge into the Rio Grande. The 

 drainage is practically out of the Rio Grande into the valley. . . . 



" The ground waters of the valley retain the characters of the mountain 

 waters in a noteworthy degree, and . . . have their own characteristics, 

 which ai'e pronounced enough to affect those of the Rio Grande water if any 

 significant volume of them is mingled with it. The alkalis, that is, salts that 

 collect in the surface portions of the soil or appear as efflorescences, are of three 

 types. These types are (1) plain sulphates, soda and lime being the predomi- 

 nant bases (this type is the predominant one) ; (2) sulphates and chlorids (this 

 type is not abundant though it is well distributed) ; and (3) a type in which 

 sulphates and carbonates occur (the occurrence of this type is for the most 

 part confined to the area north of the Rio Grande). Solutions of these alkalis 

 do not find their way into the Rio Grande in sufficient quantities to noticeably 

 modify the composition of its water. 



" The valley is an exceedingly large artesian basin, but the waters are of 

 two characters. Those of the southern portion and the rim of the basin are 

 white and carry an excess of acids. Silicic is especially high, while those of 

 the northern interior portion of the basin are alkaline and usually brownish or 

 brown in color. The white artesian waters, especially those flowing from shal- 

 low wells, from 75 to 300 ft. or even more, are very similar to river or mountain 

 water and would simply increase the volume and would not change the char- 

 acter of the river water if they mingled with it. 



" The brown water is free from silicic acid and contains as good as no salts 

 except sodic carbonate. This character of the brown waters is the same for all 

 flows from the shallowest to the deepest examined, 8S0 ft. The deeper flows 

 Increase in the amount of salts held in solution without any change in their 

 character. This increase was from 22 to 108 grains in each imperial gallon. 

 These waters would change the character of the river water if they mingled 

 with it, which they appear not to do. The brown color is accidental and is due 

 to peaty material dissolved out of the aquifers themselves. ... 



" The sodic carbonate is considered as originally coming from the mineral 

 constituents of the rocks furnishing the sands and clays that form the strata 



