NOTES AND MEMORANDA. 
215 
to clear up the brownish matter accumulating in advance of the usual 
position of the nucleus when present. 
At this time the young EuglypJia measured 0-116 mm. long and 
0*064 mm. broad. 
The sarcode of the parent now contracted at the middle, leaving a 
space between it and the test. The same change occurred in the child. 
The sarcode of the parent next cleared up in the vicinity of the mouth, 
then separated from that of the offspring, and retracted a short dis- 
tance within the mouth. 
At 5 minutes to 8 o’clock the two Euglyphoe bent slightly from 
side to side, protruded delicate pseudopods, and in two minutes after- 
wards were completely separated, with their mouths directed downward, 
and their fundi turned towards my eye. 
Half an hour after separation a pale nucleus had made its appear- 
ance in both individuals, occupying the usual position, and measuring 
0 • 028 mm. in diameter. Two or more contractile vesicles disappeared, 
and reappeared around the position of the nucleus. While the parent 
retained the original size, the young Euglypha was 0-12 mm. long by 
0*064 mm. broad. 
From this observation of the mode of multiplication of EuglypJia^ 
coupled with that of Cienkowski on the multiplication of Ghlamy- 
doplirys, it may be inferred that all the test-bearing Rhizopods multiply 
in a similar manner. 
The mode of multiplication of these Rhizopods reminds one of the 
mode of production by division of the Desmids, and in observing the 
process in the EuglypJia I was forcibly struck with its resemblance to 
the mode of production of ArtJirodesmus octocornis. The production 
of the young Rhizopod would correspond with that of a half cell of a 
Desmid. 
Apparent Discriminative Power in the Selection of Food hy a Helio- 
zoon . — Professor Leidy also stated to the Academy that he had on 
several occasions observed actions in the Rhizopods apparently in- 
dicating a discriminative power in the selection of food. It was 
certain that they generally swallowed living Algae and Animalculae, 
and avoided dead ones. He recently had observed a Heliozoon eject 
an article which appeared to indicate a discriminative power. The 
Heliozoon was Acanthocystis spinifera. The genus differs from 
Actinophrys in being provided with siliceous rays in addition to the 
ordinary soft rays. The former emanate from minute disks, forming 
as it were a sort of flexible armour to the body of the Acanthocystis. 
While examining an individual, a rapidly moving oval flagellate Infuso- 
rium, as it was supposed to be, came into contact with several of the 
soft rays. The Infusorium was paralyzed ; it assumed a globular shape 
and became quiescent. It was gradually drawn towards the body of 
the Heliozoon, which projected its armour to meet it, but quickly 
withdrew it again, and the Heliozoon was pushed off beyond the 
siliceous rays. The same movements were repeated, and then the 
Infusorium remained outside the siliceous rays. The objects were 
examined from time to time for several hours. The Infusorium was 
no more drawn towards the body of the Heliozoon. After a time it 
