no REMINISCENCES OF 



On receiving a liberal supply of the Boston shells 

 from Mr. Reckitt, I tried an experiment that proved 

 so successful that I adopted it ever afterwards when 

 separating the more minute Foraminifer shells, from 

 the ooze dredged up from the deeper seas. The 

 material was first thoroughly dried before a fierce fire, 

 and then rapidly stirred up in a broad-mouthed 

 vessel filled with cold water. The result was that 

 the chambered cavities of the Foraminiferous shells, 

 being now full of air, floated to the surface, whilst a 

 gentle stirring with the hand soon sent all the 

 particles of sand and mud to the bottom. The 

 surface residue was now floated off into a shallow 

 dish and allowed to dry. On examining the material 

 thus obtained from the Boston sand, I found that it 

 almost wholly consisted of a mass of beautiful and 

 varied pieces of Foraminiferous shells. I further 

 discovered that the aggregation was especially rich 

 in examples of Walker's genus, Lagena. Walker 

 had already seen and given names to about five of 

 these objects. After a minute study of my specimens 

 I prepared a memoir, in which they were figured and 

 described. But the study of these objects led me to 

 an important conclusion, which I discovered at a 

 later period to be applicable to the entire group 

 of the Foraminifera. I demonstrated that such 

 was their capacity for variation at different ages 

 and from different localities, that long strings 

 of genera and species might be arranged in 

 linear series, rendering it possible that all the 



