Ascidians Type-slides. 305 



specimens of Ascidia mentula. I told him I thought 

 I could get them for him through you, as the form is 

 not rare in the Clyde." 



As it proved, however, the Clyde would not, at any 

 rate at the time, yield the required specimens. With 

 some correspondents there would probably have been 

 no more to be said. The objects asked for had been 

 sought and not found, and consequently could not in 

 reason be expected to be sent. But the following 

 letter will show that Robertson dealt with the asci- 

 dians as Mahomet did with the mountain ; if they 

 would not come to him, he made up his mind to go 

 to them. Norman, writing from Burnmoor on Sep- 

 tember 21, says 



"Mv DEAR ROBERTSON, 



"Your letter from Oban directed to Ware 

 has been forwarded, and reached me here this morn- 

 ing. It is really extremely kind, and shows a real 

 anxiety to promote the interests of science that you 

 should have gone all the way to Oban to get the 

 ascidians, and I am very glad that having thus gone 

 you were not unsuccessful in the search. Please 

 kindly send the specimens to Professor Huxley, care 

 of the Curator, the University Museum, Edinburgh." 



On November 28, in the same year, Norman writes 

 in regard to an invention of Robertson's, which will 

 be found described among others in Appendix A : 



"Mv DEAR ROBERTSON, 



" Many thanks for your charming type- ; 

 slides. They are wonderful proofs of your skill and 



