PHYSIOLOGICAL. 
Gen. Sub. 43 
Study of animals which are “ skiopfcic,” “ photoptic,” and “ photo- 
skioptic,” without being “ iconoptic ; ” Nagel (385, 386). 
Sense of Cceleniera : Centre of polar area in Beroe ofoata appears to be 
an organ sensitive to mechanical stimuli Umbrella and velum of 
Carmarina haslata insensitive to mechanical, chemical, or thermal stimuli. 
Anemones feebly sensitive except in tentacles. No sensitiveness to sound 
discovered, and little to light ; Nagel (385). 
Smell and Taste ; Nagel (386). 
Nervous system and movement in earthworms ; FriedlAnder 
(172). 
Functions of integumentary organs iu fishes, annelids, &c. ; Leydig 
(306). 
Function of equilibration : The simplest means of orientation is that 
afforded by a difference between the specific gravity of the organism and 
that of the medium. Other methods ; Betiie (38, 39). 
Equilibrating function ; Lee (300). 
Functions of Labyrinth ; Wegener (561). 
Brain-physiology of worms : Experiments oa Thysanozoon brocchii , 
Planaria torva , Cerebratidus marginatus , Nereis , Lumbricus, Hirudo , &c. 
The anterior ganglia act in a general way as “ brain ; ” there seems to 
be no associative memory or consciousness ; there is no parallelism be- 
tween the brain functions of the several species and their systematic 
position ; Loeb (313). 
History of nerve cells : In cerebellum of old man, age 92, Purkinje’s 
cells were shrivelled and fewer by 25 per cent., in comparison with man 
of 47. In spinal ganglion cells more degeneration. Nerve cells more 
numerous in young bees than in old, in proportion of 1 : 2 9. With 
age the number of cells decreases, the nuclear content decreases, and 
nucleoli are rarely distinguishable ; Hodge (247). 
Changes of nerve cell under electric stimulation ; Hodge (246). 
Changes in nerve cells during functional activity : During rest several 
chromatic materials are stored up in the nerve cell, and these materials 
are used up by it during the performance of its function. Activity is 
accompanied by an increase in size of the cells, the nuclei, and the 
nucleoli of sympathetic, ordinary motor, and sensory ganglion cells. 
Fatigue of the nerve cell is accompanied by shrivelling of the nucleus, 
and probably also of the cell, and by the formation of a diffuse chromatic 
material in the nucleus ; Mann (325). 
Nature of a ganglion ; Morat (373). 
Introduction to comparative psychology : Psychological discussion of 
animal intelligence and instinct, perceptions and sensations ; Lloyd 
Morgan (374). 
Instinct and intelligence in chicks and ducklings ; Lloyd Morgan 
(375). 
Physiological “explanation” of psychical phenomena; Exner 
(146). 
Origin of Instincts : Instincts, to whose evolution we have no clue, 
