August 15, 1913] 



SCIENCE 



239 



top several feet above the level of the water in the 

 shaft. The water flowing from the artesian well 

 fell into the shaft which became filled with water 

 to the top of the discharge pipe. In this manner 

 the water from the artesian well and the seepage 

 water from the shaft and tunnel were mixed. 

 Soon after the completion of this artesian well a 

 sample of this water was sent to us for examina- 

 tion. We expected to find either no bacteria or 

 only a very few. We found, however, that the 

 bacterial count went up to 42 per cubic centimeter 

 with two colonies of colon bacilli. Chemical exam- 

 ination likewise showed evidence of contamination 

 with sewage material. The reason for this was not 

 explained until after a personal inspection and 

 subsequent examination showed that the contam- 

 ination occurred in the large shaft with water 

 from the shaft and tunnel. The water taken di- 

 rectly from the well did not show any evidence of 

 pollution. We believe that the water of the tunnel 

 and shaft comes largely quite directly from the 

 river through fissures in the rocks and hence is not 

 properly filtered. 



Bacterial Activities amd Crop Production: P. E. 



Beown. 



The importance of soil bacteria in bringing 

 about the change of insoluble material containing 

 the essential plant food constituents into forms 

 which are available for the feeding of crops is 

 emphasized as a basis for the assumption that 

 there should be some relation between essential 

 bacterial activities and actual crop production. 

 Determinations of total numbers of organisms 

 using an albumen agar and estimations by the 

 beaker method of the ammonifying power and the 

 nitrifying power of the soils of several series of 

 field plots were made. Comparison of the results 

 of these bacteriological studies with the actual 

 crop yield revealed the fact that in practically 

 every case a soil showing greater numbers of or- 

 ganisms, greater ammonifying power and greater 

 nitrifying power than another soil showed like- 

 wise greater crop production. Fresh soil with a 

 solution of casein added for ammonification and a 

 solution of ammonium sulfate added for nitrifica- 

 tion allowed of the greatest difiierentiation accord- 

 ing to bacterial activities of the soils tested. 



The Monterey Conifers: Thomas H. MacBkide. 



A discussion of the distribution and habits of 

 the four conifers, Cupressus macrocarpa Hartweg, 

 Cupressus Goveniana Don, Finns muricata Don 

 and Pinus radiata Don, which are found in the 

 vicinity of Monterey, California. 



Quercus iorealis Michx. f.: B. Shimek. 



This is generally regarded as a synonym of 

 Q. rubra, but it seems to be quite distinct. The 

 paper contains a discussion of its characters and 

 its distribution in Iowa. 



The Sedges of Henry County: John Theodore 



BUCHOLZ. 



A discussion of the physiography and topog- 

 raphy of Henry County with special reference to 

 the distribution and habitats of the sedges, fol- 

 lowed by an annotated list of the species found in 

 Henry County. 



The Diclinous Flowers of Iva xanthiifolia Nutt.: 



CLirFOED H. Fakk. 



The placing of this species among the Com- 

 positse is favored by the fact that the walls of 

 adjacent stamens unite by the fusion of contigu- 

 ous cutinized layers. Furthermore, the flowers are 

 arranged in a capitulum in concentric cycles of 

 five flowers each. The outer cycle consists solely 

 of pistillate flowers, and the remaining cycles are 

 made up entirely of stamiuate flowers. The abor- 

 tive stamens of the pistillate flower appear after 

 the carpels, and were seen occasionally to have 

 developed into pollen-bearing members. It is evi- 

 dent that the stamens of the marginal flowers, 

 being epigynous, would come in contact with the 

 enlarged ends of the corollas of adjacent staminate 

 flowers and with the apices of the floral and in- 

 volucral bracts. That this crowding may have 

 caused the abortion of these stamens seems cred- 

 ible. The abortive pistil of the staminate flower 

 doubtless aids in dehiscence by engaging the hook- 

 like tips of the stamens. It possesses no ovary, 

 but early develops a notch on its apex, which sug- 

 gests its derivation from the typical bifid form. 

 The gynceeium of a flower is more susceptible, 

 both in structure and in function, to the effects 

 of desiccation than is the androecium. The cen- 

 tral flowers of this form are more exposed than 

 the marginal on account of the following cir- 

 cumstances: their distance from the involucral 

 bracts, their tardy appearance, the minuteness or 

 absence of floral bracts of the disc flowers, the 

 convexity of the receptacle, and the remoteness of 

 the disc flowers from the main vascular supply. 

 It therefore seems that exposure to desiccation 

 through many generations will explain the abor- 

 tion of the pistil in the disc flowers. Excessive 

 exposure of certain flowers and excessive protec- 

 tion of others are therefore suggested as the 

 major causes for the origin of decline in this 

 species. 



