‘TENTH ANNUAL MEETING. 87 
tions have led me to reduce, on an extensive scale, the number 
of species in the family. 
So, in the genus Anguilla, I find but four species: Anguzlla vul- 
garis, occurring throughout the northern hemisphere, in the new 
world as well as the old. <Axngutlla marmorata and A. mowa of the 
Indian Ocean, and Anguilla megalostoma of Oceanica. 
“There are at least four distinct types, resulting from the com- 
bination of a certain number of characters; but the study of a 
very large number of specimens belonging to these four spe- 
cific types has convinced me that each of these characters may 
vary indepenedntly, and that consequently certain individuals 
exhibit a combination of characters belonging to two distinct 
types. It is therefore impossible to establish clearly defined 
barriers sepa rating these four types. 
“The genus Anguilla exhibits, then, a phenomenon which is 
also found in many other genera, and even in the genus Homo 
itself, and which can be explained in only two ways: Either 
these four forms have had a common origin, and are merely 
races, not species, or else they are distinct in origin, and are true 
species, but have been more or less intermingled, and have pro- 
duced by their mingling intermediate forms which coexist with 
those which were primitive. Science is not in the position to 
decide positively between these alternatives.” 
ANCIENT BELIEFS CONCERNING THE REPRODUCTION OF THE EEL. 
The reproduction of the eel, continues Benecke, has been an 
unsolved riddle since the time of Aristotle, and has given rise to 
the most wonderful conjectures and assertions. Leaving out of 
question the old theories that the eels are generated from slime, 
from dew, from horsehair, from the skins of the old eels, or from 
those of snakes, and the question as to whether they are pro- 
duced by the female of the eel or by that of some other species 
of fish, it has for centuries been a question of dispute whether 
the eel is an egg-laying animal or whether it produces its young 
alive ; although the fishermen believe that they can tell the male 
and female eels by the form of the snout. A hundred years ago 
no man had ever found the sexual organs in the eel. 
