The Vegetable Individual in its relation to Species. 63 ~ 
internal problem of its existence to a consummation,—to complete 
the metamorphosis into flower and fruit. This remarkable phe- 
nomenon,—which is a very frequent one in the vegetable king- 
dom, and is one of the essential characteristics of many of the 
most important families of plants, e. g., the grasses, Synanthe- 
ree, Laliatifloree, Crucifere, Leguminose, etc.,—is the same 
as that which in the animal kingdom (in whose lower orders it 
re-appears) was, we cannot say discovered, but brought to a 
ioe 9 pelaapieny not mney since by the Norwegian natural- 
s,* completed and confirmed by von Siebold’s investiga- 
tions into the history of the doselopinent of Medusa aurita,t 
b and soon after substantiated in its universality by the Dane, 
: Steenstrup, under the name of “alternation of generation,” or 
propagation and development by alternate series of qeorintanet 
ingle cases of alternation of generation had been alr ready care 
fully observed : >$ but they were too much in opposition to the 
— mode of reproduction to be understood in their true mean- 
- 
| ; be Wiegmann’s Archiv, 1844, where the observations published in the author's 
. ‘ er works, on the adolescent states of Medusa’ are complet: Phe ron concluded. 
: chs Coy sige 154% 
_§ Bonnet’s industrious observations, the first that were made, of t ernating 
mode of reproduction of Aphis, published in his Traité de ‘osetolgie in 1745, 
Iso Cham obse 
0, belong here. A amisso’s arene rvations - 
Ration of generation in Sale described i ie Memoir Animalibus qui 
1 nneana, 41 Fragments in regued to the alternation of 
ea pte of Trematode were known, (but as such they did seem very eni 
Y Bojanus's Beschreibung d. kénigsgelben er (the “ sere of Zrem ac- 
cording to Stee strup) aus welchen Cercarien (the larve of the final nal generation) 
heraus erauskommen sis, 1818 ’ vee 
, and by v. Bawer’s important w it 
ait Bue ephalus, aucine tgs Kenntniss d. niederen Thiere. Act. rig cur, va 
Bi Of the later wich by whi h the field of alternation of generation ‘has been 
ve es ips rticular; Sars: — —— Norwegie, 1846, in 
i n opsis, 
Diphyes and Salpa—Van Beneden: Recherches mbryogénie des ‘Tubulaires 
(1 814); Mém, sur les nae i de la céte seb ton in toe mém. de 
Acad. roy. de ee . XVII); Recherches sur l’anat., la a physiol., et le dével. 
as Rees (i (Mém. de I’Acad. roy. ote “ T. uae " gerne Sur le dével 
toe ee : bi 
8. p. 174); Beker. d. Fortpfi. u. Entw. der Biphoren (Froriep’s neue Notizen, No, 
$88, 1846)— Buse 2 Balk ie Anat. u. Entw. d. Infusorien (Arch. f. Naturgesch. 
2 nation’ > oe great raportaece must be attributed to the discovery of alter- 
of generation in cae he darkness — ger oe seh on Loe his- @ 
lling the Hs 
of the fhemsbc and de vel f Eni _— v. Sie 
tr pregnant sibs seg e Wagner’ I Php + 
840 (Article: P meuaitens 
