Jan., 1907.] Stellate Hairs and Peltate Scales. 51 



normal yet gave the lowest corn yield on record. This is ac- 

 counted for by the fact that the whole summer was cold and wet ; 

 the number of days between the spring and fall frosts was the 

 least on record. 



It is very apparent from the charts that to produce the best 

 yield of oats June and July or both must be moderately cool and 

 dry. 



Barley is not so important in this county but from the rec- 

 ords given the summer should be warm and dry. 



The best potato years have been those with a cool summer, 

 with a fair amount of rain in June and July and with a dry Sep- 

 tember. 



Rye and clover are affected by winter conditions much as 

 wheat is affected. The best yields of hay other than clover are 

 with an abundant rainfall in April, May and June. 



The dates of blossoming of fruits depends to a marked de- 

 gree upon the temperature of March and April. In general poor 

 fruit yields have been preceded by cold winters and good yields 

 by comparatively mild winters. 



STELLATE HAIRS AND PELTATE SCALES OF OHIO PLANTS. 



Edna M. McCleery. 



All hairs and scales serving merely as a covering, without 

 reference as to their origin, have practically one function, that of 

 protection. They serve as a protection in two ways; first, by 

 preventing evaporation by the wind, and second, by preventing 

 the direct rays of the sun from shining on the surface of the leaf 

 and thus causing excessive transpiration and injury to the chloro- 

 phyll. With this function in mind it is easily seen how much 

 more effective the interlaced points of stellate hairs or scales 

 would be, than simple short hairs. 



There are two divisions of stellate pubescence; first, that in 

 which the leaf is covered with hairs having a star shaped or many- 

 pointed top and a single stalk by which they are attached to 

 the surface of the leaf, and second, that in which the leaf is 

 covered with simple hairs arranged in tufts from one point. The 

 illustration given of a stellate hair of Lepargyraea canadensis 

 (Fig. 3) shows plainly the many-pointed top and the single stalk. 

 The stellate hairs of Croton monanJ;hogynus (Fig. 7) and of the 

 Solanums (Figs. 17, 18, 19) do not have the long stalks on the 

 under side by which they are attached to the surface of the leaf, 

 but instead they are almost sessile. They have, however, a 

 single point or branch which rises from the center and stands at 

 right angles to the remainder of the hair and to the surface of the 



