I nter-Relationships of Protista and Primitive Fungi. 167 
possessing both kinds of appendage. Such forms may be regarded 
as giving rise to the Infusoria; indeed the only changes required in 
order to obtain a typical simple Ciliate from such a form as, say, 
Trichonenia gracile would be the loss of the flagellum, the special¬ 
isation of the nuclear apparatus and the acquisition of an oral groove 
or mouth-spot. A mouth-spot is apparently present in some of these 
“ Cilioflagellates ”— e.g. Stephanomonas , and possibly Lophomonas 
and Spironenia also ; Dinennympha has lost the anterior flagellum ; 
Fio. 3. Forms possibly Transitional between Flagellata and 
Infusoria. A, Stephanomonas locellus Kent. B, Lophomonas blattarum Stein. C, 
Mitophora dubia Perty. D, Spironema multiciliatum Klebs. E , Trichonema hirsutum 
From. F, Trichonema gracile Moeb. G, Heteromastix proteiformis Clark. H, 
Leidyonella cordubensis Frenz. I, Trichonympha agilis Leidy. J, Pyrsonympha 
vertens Leidy. K, Dinennympha gracilis Leidy. 
while the fact that the dual nuclear apparatus character has appar¬ 
ently arisen independently in the two distinct offshoots of the 
Protomastigineae which are classed together under the heading of 
Trypanosomes—though the Trypanosome nuclear apparatus is not, 
it must be admitted, heterokaryote in the same sense as the Infusoria 
—reduces the difficulty presented by this very characteristic feature 
of the Infusoria. That the trichocysts or stinging capsules so 
common in Infusoria have arisen more than once in the evolution of 
Protista is indicated by the presence of these structures in some 
Peridiniales and allied Flagellata ( Pouchetia , Polykrikos). 
