EXTRACTS FROM MR. DARWIn's LETTERS. 457 



Art. XLIII. — Extracts of Letters from C. Darivin, Esq., to 

 Professor Henslow. 



PRINTED FOR PRIVATE DISTRIBUTION. 



" St. Iago (Cape de Verd Islands) is singularly barren, and 

 produces few plants or insects : on the coast I collected many 

 marine animals, chiefly gasteropodous mollusca (I think some 

 new)."— P. 3. 



" Rio de Janeiro. — I am now collecting fresh water and 

 land animals ; if what was told me in London is true ; viz. that 

 there are no small insects in the collections from the tropics, 

 I tell entomologists to look out, and have their pens ready for 

 describing. I have taken as minute (if not more so) as in 

 England, Hydropori, Htjgroti, Hydrohii, PselapJii, Staphy- 

 lini, Curculiones, Bembidia, 8cc. &c. It is exceedingly inte- 

 resting to observe the difference of genera and species from 

 those I know; it is however much less than I had expected. 

 I have just returned from a walk ; and, as a specimen how little 

 the insects are known, Noterus, according to Die. Class, 

 consists solely of three European species. I, in one haul of 

 my net, took five distinct species." — P. 5. 



" Monte Video. — 1 made an enormous collection of Arach- 

 nidae at Rio ; also a good many small beetles in pill boxes, 

 but it is not the best time of the year for the latter." — P. 5. 



" Amongst the lower animals, nothing has so much interested 

 me as finding two species of elegantly coloured Planarice (?) 

 inhabiting the dry forest ! The false relation they bear to 

 snails is the most extraordinary thing of the kind I have ever 

 seen. In the same genus (or more truly family) some of the 

 marine species possess an organization so marvellous that I can 

 scarcely credit my eyesight. Every one has heard of the 

 discoloured streaks of water in the equatorial regions. One I 

 examined was owing to the presence of such minute Oscilla- 

 toria, that in each square inch of surface there must have been 

 at least one hundred thousand present." — P. 6. 



" I might collect a far greater number of invertebrate 

 animals if I took up less time with each, but I have come to 

 the conclusion that two animals, with their original shape 

 noted down, will be more valuable than six with only dates and 

 place." — P. 6. 



NO. v. VOL. III. 3 N 



