1876.] A Remarkable Life History and its Meaning. 647 
derful changes which so many of the invertebrates undergo in 
passing from the egg to the perfect form ; and the existence of an- 
imals whose children resemble their grandparents, while they are 
a sa their parents, was So opposed to all that was known 
a amisso s discovery at first met with nearly universal ridi- 
eand discredit. In fact, one of the greatest of naturalists is 
-stated to have said that he could much more easily credit Chamis- 
so's romance of Peter Schlemihl than his observations upon Salpa. 
eee ees 
ON G 
aO 
Fig. 
eel het young bud-tube, from a solitary Salpa: b, outer tunic; c, wall of 
tube; yy, id Nagas 1, blood-channel; 2, cavity of tube; 4, constrictions upon the 
the lower invertebrates was 
At this time our acquaintance with 
and it was soon found that 
o with wonderful rapidity, 
i. animals, especially the intestinal worms, g0 through an 
ation substantially like that described by Chamisso as tak- 
A i Salpa ; the second generation being very different in 
fi ai torm, and, in many cases, in structure also, from the 
i. Within a few years from the time of publication of Cha- 
; on Alternation of Genera- 
al information was given 
t was shown to be not 
Moire ars; and the able me- 
i of Sars, Krohn, Huxley, Vogt, and Leuckart have given 
"S@ nearly complete account of its life history. All these natu- 
agree in holding the opinion that Salpa presents a real 
