RESEARCHES ON THE CILIO-FLAGELLATA, ELE 
serving accurately, and the still greater difficulty of interpreting 
correctly your observations when made. You may depend 
upon it, that, without a personal knowledge at first hand of 
facts, you can never weigh the value of evidence ; you can never 
tell whether a statement may be relied on, or whether it is 
founded on doubtful or insufficient observations ; you can never 
feel sure that the argument for or against a theory is not special 
pleading—that is, whether adverse evidence has not been sup- 
pressed. But if you begin by obtaining a broad basis of facts 
from personal observation, you will readily acquire a complete 
grasp of principles, and you will then be able to take them out 
of their own immediate subject and apply them with success to 
the higher study of sociology. Sosure am I of this that I feel 
confident the day is not far distant when a knowledge of the 
principle of selection will be considered indispensable for the 
historian, the statesman, the theologian, and the journalist—for 
all indeed who aspire to guide their fellow men; and biology 
will then take its place as a necessary part in every curriculum 
of Arts. 
RECENT RESEARCHES ON THE CILIO- 
PREAGEELATSA. 
ee es 
BY, EROL.. Ce [EP ERRY PARKER. 
— OS 
This interesting group of Infusoria has lately received the 
attention of a Danish zoologist, Mr. R. S. Bergh, who publishes 
an elaborate monograph on the subject in the last number of 
Gegenbaur’s “ Morphologisches Jahrbuch.”* 
The Cilio-flagellata are intermediate in characters between 
the flagellate and the ciliate Infusoria. Like the Flagellata, they 
possess, as their chief organ of locomotion, a long whip-lash- 
like cilium or flagellum, in addition to which they are provided, 
like the Ciliata, with ordinary small vibratile cilia, usually 
restricted to an incomplete annular band round the body. 
The form of the body is always bilaterally asymmetrical ; 
that is, there is a clear distinction between dorsal and ventral 
aspects, anterior and posterior ends, and right and left sides ; 
but the two latter never resemble one another perfectly, the body 
being divisible into two unequal and dissimilar portions by a 
median vertical plane. The variations in the form of the body 
are very great ; it may be compressed from before backwards, or 
from above downwards, or from side to side, and may be pro- 
*R.S. Bergh, ‘‘Der Organismus der Cililoflagellaten, eine phylogenstiche 
Studie.” Morph. Jahrb., Bd. VII., 2 Heft, pp. 177-288, pl. xii-xvi. 
