\6 EARLY LETTERS [Chap. 1 



Letter 5 me ; some of his woodcuts came so exactly into play that 

 I have only to refer to them instead of redrawing similar 

 ones. I had my barometer with me, I only wish I had 

 used it more in these plains. The valley of S. Cruz appears 

 to me a very curious one ; at first it quite baffled me. I believe 

 I can show good reasons for supposing it to have been once 

 a northern straits like to that of Magellan. When I return 

 to England you will have^some hard work in winnowing my 

 Geology ; what little 1 know I have learnt in such a curious 

 fashion that I often feel very doubtful about the number of 

 grains [of value ?]. Whatever number they may turn out, I 

 have enjoyed extreme pleasure in collecting them. In T. del 

 Fuego 1 collected and examined some corallines ; I have 

 observed one fact which quite startled me : it is that in the 

 genus Sertularia (taken in its most restricted form as [used] 

 by Lamoureux) and in two species which, excluding compara- 

 tive expressions, I should find much difficulty in describing 

 as different, the polypi quite and essentially differed in all 

 their most important and evident parts of structure. I have 

 already seen enough to be convinced that the present families 

 of corallines as arranged by Lamarck, Cuvier, etc., are highly 

 artificial. It appears that they arc in the same state [in] 

 which shells were when Linnaeus left them for Cuvier to 

 rearrange. I do so wish I was a better hand at dissecting, 

 I find I can do very little in the minute parts of structure ; 

 I am forced to take a very rough examination as a type for 

 different classes of structure. It is most extraordinary I can 

 nowhere see in my books one single description of the 

 polypus of any one coralline excepting Alcyom'uw Lobularia 

 of Savigny. I found a curious little stony Cellaria 1 (a new 

 genus) each cell provided with long toothed bristle, these are 

 capable of various and rapid motions. This motion is often 

 simultaneous, and can be produced by irritation. This fact, as 

 far as I can see, is quite isolated in the history of zoophytes 

 (excepting the Flustra with an organ like a vulture's head) ; it 

 points out a much more intimate relation between the polypi 

 than Lamarck is willing to allow. I forgot whether I 

 mentioned having seen something of the manner of propa- 

 gation in that most ambiguous family, the corallines ; I feel 



1 Cellaria, a genus of Bryozoa, placed in the section Flustrina of the 

 Suborder Chilostomata. 



