Royal Institution. 505 



of the Flora of the Tertiary Epoch in Central Europe. By this it 

 appears that — 



1. The Eocene Flora is composed of 127 species, of which 115 be- 

 long to Algae, Characeae, Ulvaceae, Palmae, Naiadaceae, Malvaceae, 

 Sapindaceae, Proteaceae, Papdionaceae, and Cupressineae. 



2. Miocene Flora, 130 species, of which 69 are Algae, Palmae, 

 Naiadaceae, Apocynaceae, Aceraceae, Plataneae, Lemnaceae, Papi- 

 lionaceae, Quercineae, Myricaceae, and Abietineae. 



3. Pliocene Flora, 259 species, of which 222 are Algae, Fungi, 

 Mosses, Ferns, Palms, Ericaceae, Ilicineae, Aceraceae, Celtideae, 

 Rhamnese, Papilionaceae, Juglandaceae, Sahcineae, Quercineae, Be- 

 tulineae, Taxineae, Cupressmeae, and Abietineae. 



The Eocene species are allied to genera now found in intertropical 

 regions, India, Asiatic Islands, and Australia ; some are peculiar to 

 the Mediterranean region. The Aquatics, which form nearly one- 

 third of the Flora, are related to genera now found in temperate 

 regions of Europe, and in North America. 



The Miocene species belong to genera found now in India, Tropical 

 America, and other intertropical regions, but of which the greater 

 portion inhabit subtropical and temperate regions. Some are genera 

 found in India, Japan, and north of Africa. 



The climate of Europe during the Tertiary Epoch appears to have 

 been becoming more and more temperate by a gradual process of 

 cooling. 



ROYAL INSTITUTION'. 



Upon Animal Individuality. "By Thomas H. Huxley, F.R.S., 

 Assistant-Surgeon R.N. 



The Lecturer first briefly described the structure of the Diphydae 

 and Physophoridae — pointing out the general conformity of these 

 animals with the common Hydra. 



They differ, however, in this important respect ; that the body 

 in which the eggs are developed is in Hydra a simple process ; while 

 in the Diphydae and Physophoridae the corresponding body presents 

 every degree of complication from this form to that of a free- 

 swimming, independent " Medusa." 



Still more striking phaenomena were shown to be exhibited by the 

 SalpcE. In this genus each species has two forms. In the example 

 chosen these forms were the S. democratica and the jS\ mucronata ; 

 the former is solitary and never produces ova, but developes a pecu- 

 liar process, the " gemmiferous tube ; " upon which and from which 

 the associated Salpce mucronata are formed by budding. 



Each of these carries a single ovum, from which the first form ia 

 again developed. 



The Salpa mucronata, which is thus produced from the Salpa de- 

 mocratica, is just as highly organized as the latter. It has as com- 

 plete a circulatory, nervous, and digestive apparatus, and moves 

 about and feeds as actively ; no one unacquainted with its history 



Ann. % Mag. N. Hist. Ser. 2. Vol. ix. 33 



