26 A JOURNEY IN BRAZIL. 
he will work out the whole ; and so I believe when the laws 
of embryological development are better understood, natu- 
ralists will have a key to the limits of these cycles of growth, 
and be able to appoint them their natural boundaries even 
from partial data. 
" Next in importance I would place the Tapirs. This is 
one of a family whose geological antecedents are very 
important and interesting. The Mastodons, the Paloeothe- 
rium, the Dinotherium, and other large Mammalia of the 
Tertiaries, are closely related to the Tapir. The elephant, 
rhinoceros, and the like, are of the same family. From its 
structural standing next to the elephant, which is placed 
highest in the group, the embryology of the Tapir would 
give us a very complete series of changes. It would seem 
from some of the fossil remains of this family that the 
Pachyderms were formerly more nearly related to the 
Ruminants and Rodents than they now are. Therefore it 
would be well to study the embryology of the Capivari, the 
Paca, and the Peccary, in connection with that of the Tapir. 
Lastly, it will be important to learn something of the em- 
bryology of the Manatee or Sea-Cow of the Amazons. It is 
something like a porpoise in outline, and seems to be the 
modern representative of the ancient Dinotherium." 
April ~l'2th. The lecture to-day was addressed especially 
to the ornithologists of the party, its object being to show 
how the same method of study, that of testing the classifi- 
cation by the phases of growth in the different groups, 
might be applied to the birds as profitably as to other types. 
We have made good progress in the last forty-eight hours, 
and are fast leaving our friends " the trades " behind. The 
captain promises us smooth waters in a day or two. With 
the dying away of the wind will come greater heat, but as 
