^90 Roosevelt Wild Life Bulletin 



obtuse as to take Embody's remark literally and as seriously intended 

 when it may have been merely to emphasize the contrast in the 

 results of his temperature observations with the long standing belief 

 that 68° F. was the dead line in the upward temperature range for 

 brook trout. 



Be that as it ma}-, it would appear to the writer that in planting 

 trout the slogan, " saf et}- first," should be regarded, until it is estab- 

 lished that everywhere and under all conditions 75° F. is well 

 within the natural temperature range. If it is proved to be so, it 

 will not signify that a new adaptation is taking place but that it is 

 one condition which is comprised in the consummation of thousands 

 of years of adaptations to changing environment and other condi- 

 tions through a complex of natural forces and " factors " which 

 has been indefinitely referred to as " natural selection."' 



In the study of conditions of the streams in Allegany State Park 

 in August, 1922, no trout were observed below the wooded region. 

 In Quaker Run the temperature varied from 52 to 67 degrees F., 

 being coldest in the upper waters and progressively rising down- 

 stream. The temperatures were taken on different dates from 

 August I to August 2^, at different times of day from about 10 a.m. 

 to about 4 :30 p.m. 



From the upper waters to a certain point in the stream the 

 temperature averaged 53.7 degrees and at no time exceeded 55 

 degrees, and that figure was observed near the place mentioned, 

 simply indicating a transition into the warmer waters below. Below 

 the said point the temperatures ranged from 58 to Gy degrees, 

 averaging about 61.7 degrees, from August 2 to August 28, between 

 10 a.m. to 3.15 p.m.. the higher readings being found lower down 

 and latest in the season. It is interesting to find that in the neighbor- 

 hood of this point a notable limitation of the fish distribution occurs. 

 Certain species occurring below do not occur above. Others which 

 continue to some distance above these are not found still further 

 up. Others continue still higher, then cease. And, finally, onh' 

 one form is found associated with the brook trout throughout. 



At the precise point referred to is a large pool in which two 

 good-sized brown trout were obser\-ed (figures 38, 39). One 

 fingerling brown trout was found a short distance above. While 

 brook trout occurred throughout the wooded section of the stream, 

 they were most abundant above the point mentioned. 



A small tributary- stream joining Quaker Run some considerable 

 distance above this point showed a temperature of 55 degrees on 

 August 7. It contained a good many small trout for the extent 

 of the stream. On the same day a mere rivulet some distance below 

 this tributary showed a temperature of 62 degrees. It contained 

 some A-oung trout. Below this another rivulet of about the same 

 size showed, on August 11. a temperature of 56 degrees. 



One of the most considerable tributaries of Quaker Run joined 

 the stream near the previously mentioned dividing point. The 

 temperature taken on August 11, 12 and 14, in different sections 

 of the brook from 9:30 a.m. to 3:00 p.m. ranged from 54 to 61 



