JET. 48.] LETTER TO HIS SISTER. 147 



You asked me at the last Club dinner to look again at the 

 Supplement you last published. I have done so. I do not quite 

 agree with [S. P.] Woodward's numbers, as I make the species 

 common to the Eed and Norwich Crag greater. The difference, 

 however, is not great or important, nor are my own lists suffi- 

 ciently complete to give a definite answer. The general fact of 

 a refrigeration, &c., I quite agree in; so also that there are 

 more recent specimens in the Norwich Crag. I base my objec- 

 tions rather upon physical grounds and points of geological 

 structure. Annexed is a rough sketch of what I think is the 

 order of sequence. I am ever truly yours, J. PEESTWICH. 



There was less literary production during 1860, yet 

 there was not less industry. The amount of field 

 geology accomplished was extraordinary. Excursions 

 were made to various parts of England to districts 

 west, south, east, north and all explored with pains- 

 taking care. Frequent journeys were also made to the 

 Somme valley : a flying visit was paid when worked 

 flints had been found in any number. His ever active 

 brain was marshalling the array of facts, and tracing 

 the outlines of the great work which was to be given to 

 the world two or three years later in the form of a 

 memoir on the Geological Age of the Drift Deposits, in 

 which remains of extinct mammalia had been found in 

 association with flint implements. This persistent de- 

 votion to his science, however, was never allowed to 

 weaken the affectionate relations which bound him to 

 his family. He was ever the same thoughtful, kind 

 brother. 



J. Prestwich to C. Thurburn. LONDON [31st March], 1860. 



MY DEAREST KATE, Very many happy returns of the day. 

 Another year has slipped away, and here is the memorable 1st 

 April and your birthday come round again. How fast time 

 moves seems to me indicated by the growth of these dear dupli- 



