FISHES OF WESTERN SOUTH AMERICA 
fish that one is obliged to reject may surfeit even one’s native helpers. There 
is a pretty rigid assorting of fishes into river and lake forms, despite the fluvial 
origin of the lakes, and despite the inundations. 
The great diversity of arboreal animals on the land is paralleled in the 
water by the large number of families of fishes and of aquatic mammals repre- 
sented. The region is yet virtually tourist-free. One may journey by steam- 
ers and launches without seeing much of the teeming life of forest and river, 
Fic. 4. DYNAMITING THE RIO DE MOLINO, along the 
western shore of Lake Titicaca. Using the dipnet is Pedro Vas- 
quez, assistant, cook, foreman, interpreter. 
or of primitive human life. Only in the-tributary streams, traveling by canoe, 
does one encounter them. Here the dolphin, manatee, otter, alligator, capy- 
bara, tapir, ete., still abound, and one comes surprisingly near seeing all the 
animals which he had hoped to encounter. 
The year 1920 was remarkable for its unusual rainfall. Not only was the 
curve for the depth of the Amazon at Iquitos higher throughout April and May 
than for many years, but also throughout the dry season. The lowest stage 
reached was some seven feet higher than the mean minimum depth. 
The exceptional inundation of April and May had destroyed much of the 
