1000 The American Naturalist. [November, 
THE EVOLUTION OF MIND. 
BY E-D. COPE. 
(Continued from page 913.) 
p the provision and care for the young animals display a great 
fertility of resource, beginning low in the scale. It is well 
known that certain Siluridæ (catfishes), Gasterosteidæ (stickle- 
backs), and Percidæ (sunfishes) of North America make nests 
for the reception of the eggs, and that they take care of the 
young. Itis not an uncommon sight, in suitable places in our 
country, to see the catfish, Amiurus nebulosus, lead about its 
shoal of young fry like a hen with her chickens. Other Siluridæ 
of South America take the eggs in the mouth, and so protect 
them. In these and similar cases we may imagine that the 
animal regards the eggs and young as part of itself, to which 
it attaches a certain value, as in ordinary self-preservation. 
Such an explanation serves in the case of the ants and bees, 
which show such care of their young. Some of the most re- 
markable cases of this kind are to be found in the Batrachia 
Salientia, an order not distinguished for intelligence in any other 
direction. In some parts of South America and Africa, where 
there is a dry season, certain tree-frogs deposit their eggs in 
masses on the branchlets and leaves of trees that overhang the 
dry beds of streams. The surface of the gelatinous albumen, in 
which the eggs are enclosed, hardens by evaporation, so that the 
latter are well protected. On the arrival of the rainy season, the 
stream below the nest begins to flow, and the nest is dissolved 
and washed into it, so that the larvze can pass their branchiferous 
larval stage successfully. It is interestingto note that the species 
which adopt this habit are not closely allied in a systematic sense, 
the African belonging to the Ranidz, and the South American to 
the Hylide. They have learned the habit independently of each 
other. Another tree-frog, of unknown species, inhabiting Japan, 
has been shown by the Rev. W. S. Holland to construct a 
