SALPIDiE. 49 



carried his day-dreams into the world of reahty, and thus 

 conjured up his wonderful vision of Salpce. More than 

 twenty years had to pass away before his statements were 

 fairly treated. Men ungifted with the poetic insight which 

 characterised Chamisso, collected and watched Salpa in 

 vain. Working in a spirit of unbelief, they saw what they 

 wished, and what was accordant with their ideas of what 

 ought to be; whereas the poet-naturalist had worked in the 

 spirit of faith, and therefore was unsurprised when he met 

 with facts and phenomena inconsistent with received human 

 knowledge. Working before his time, he was misunder- 

 stood ; but the time came when not only were his observa- 

 tions proved to be true, but when a great impulse was given 

 to natural history through them. It was the history over 

 again of all great impulses in our science. Linnreus pro- 

 claimed the metamorphosis of plants unlistened to; Goethe, 

 more happy in his time, unravelled the same great mystery, 

 and was understood, though not by all. The poetic spirit, 

 working alike in LinnaDus and in Goethe, did these things; 

 so also in Chamisso. It required a similar spirit to renew the 

 impulse in the zoological instance, as in the botanical. That 

 spirit has appeared in Steenstrup, the germ of whose theory 

 of the alternation of generations is to be found in Cha- 

 misso''s discovery of the alternation of generations in the 



The recent researches of Krohn on the Salpce of the coast 

 of Sicily-f- fully confirm the statements of Chamisso. Krohn 

 found that every Salpa which came under his observation 

 was viviparous, and that each species propagated itself by 

 an alternate succession of dissimilar generations. One of 

 these generations is represented by isolated, the other by 

 aggregate individuals (forming chains). Each isolated in- 



* Chamisso's observations were published in 1819: " Do animalibus qnibiis- 

 dam e classe vemiiura Linnreana, fasc. i. de Salpa." We owe to the Ray 

 Society and Mr. Busk an English version of Steenstrup 's most interesting trea- 

 tise. 



i" Krohn, Observations sur la Generation ct Ic Developpement des Biphores 

 Ann. Sc. Nat., August, 1846. 



VOL. I. H 



