524 



SCIENCE. 



[N. S. Vol. IV. No. 93. 



the latter part of June, 1870, explored the 

 valley of the Amazon for a distance of about 

 400 miles above Para, as well as the rivers 

 Chingu and Tapazos, two of the principal 

 tributaries of the Amazon. Prof. Prentiss 

 thus had an opportunity of studying the 

 tropical flora, and of making collections for 

 the department. The party returned early 

 in January, 1871. Among the large num- 

 ber of students who have received instruc- 

 tion from him, many have become botanists 

 or teachers of botany, and a noteworthy 

 list of names of these persons might be pre- 

 sented, several of whom occupy some of the 

 most prominent botanical positions in Amer- 

 ica. In his lectures he was deliberate, clear 

 and concise in his statement, and an easy 

 and fluent speaker. His dignified bearing 

 led many at first to regard him as unsympa- 

 thetic, but those who came to know him 

 well regarded him as a most delightful 

 companion. 



His keen interest in the work of the in- 

 dividual student, and his well chosen words 

 of approval and encouragment kindled en- 

 thusiasm among his pupils, and stimulated 

 them to renewed effort. The same gentle 

 and elevating influence, with his cultivated 

 and refined taste, exerted upon his pupils, 

 also was felt in his home and in his social 

 life, and it is to be regretted that the lack 

 of a strong constitution and reserve power, 

 coupled with failing health for a number of 

 years, prevented the production of work and 

 publications which otherwise might have 

 been expected of a man who possessed such 

 culture and natural gifts. 



Geo. F. Atkinson. 

 Cornell University. 



CURRENT NOTES ON PHYSIOGRAPHY. 

 WATERWAYS OF ENGLISH LAKELAND. 



Under the above title J. E. Marr dis- 

 cusses the origin of the river courses in 

 the lake district of northwestern England 

 (London Geogr. Journ, vii., 1896, 602-621). 



The chief streams are thought to have been 

 superposed on the deformed paleozoic rocks 

 of the region from an unconformable cover 

 of the younger strata ; Marr advocating the 

 former occurrence here of Cretaceous or 

 even of Eocene beds. Subordinate streams 

 are subsequent, being developed along weak 

 strata or along faulted belts. The lake ba- 

 sins, large and small, are not explained by 

 glacial erosion, but by drift barriers ; fuller 

 evidence on this point being promised. 

 The gradual retreat of the Pennine escarp- 

 ment, and the beheading of the Tees head- 

 waters by the steep ' gills ' that descend 

 to the Vale of Eden, are incidentally de- 

 scribed. 



In certain paragraphs there does not ap- 

 pear to be sufiicient appreciation of the 

 long perspective of events involved in the 

 history of so old a region as Lakeland, The 

 upper part of river Lune, flowing from car- 

 boniferous rocks to the higher-standing 

 paleozoic beds of Howgill fells, is given as 

 an example of antecedent drainage. Sev- 

 eral branches of the Lune, that flow from 

 the thrown to the heaved side of the great 

 Dent fault, are likewise explained as ante- 

 cedent. Here the possibility that many 

 cycles of erosion elapsed since the ancient 

 rocks of the region were deformed and 

 faulted is not clearly set forth. Yet, dur- 

 ing these cycles, it is quite possible that the 

 land forms initiated by the ancient defor- 

 mation, and the river systems antecedent 

 to or consequent upon these land forms, 

 may have suffered extensive alteration ; the 

 lands may have been more than once uplifted, 

 dissected and peneplained ; they may have 

 been drowned, buried, uplifted and stripped ; 

 and the rivers may have lost their initial 

 coutses by spontaneous adjustments to in- 

 ternal structures, by superposition, 01^ by dis- 

 placement through warping of the land sur- 

 face. The problem is not simple enough to be 

 decided merely by the direction of a stream 

 with respect to the heaved side of a fault. 



