Chapter I: Front Matter

Memoirs from the Biological Laboratory
OF THE
JOHNS HOPKINS UNIVERSITY
IV, 4
WILLIAM K. BROOKS, EDITOR

PHYSIOLOGY AND HISTOLOGY
OF
THE CUBOMEDUSÆ

INCLUDING

DR. F. S. CONANT’S NOTES ON THE PHYSIOLOGY

A DISSERTATION PRESENTED TO THE BOARD OF UNIVERSITY STUDIES
OF THE JOHNS HOPKINS UNIVERSITY
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

BY
E. W. BERGER

BALTIMORE
THE JOHNS HOPKINS PRESS
1900

PRINTED BY
The Lord Baltimore Press
THE FRIEDENWALD COMPANY
BALTIMORE, MD., U.S.A.

This Memoir is a continuation of the work upon the Cubomedusæ which was begun by the late Dr. FRANKLIN STORY CONANT, and it contains his notes of physiological experiments, as well as new results which have been obtained by Dr. E. W. BERGER from the study of material which had been collected by Dr. CONANT, who had hoped to make it the object of further study.

In order that this work may be made public as a continuation of Dr. CONANT’S researches, his sister, GRACE WILBUR CONANT, has, with the coöperation of other members of his family, made an adequate and generous provision for its publication.

For this gift, which is at once a contribution to science and a memorial of an able and promising investigator, lately student and fellow in this institution, the Johns Hopkins University returns its grateful acknowledgments.

DANIEL C. GILMAN, _President_.
W. K. BROOKS, _Professor of Zoölogy_.

CONTENTS.

PAGE
INTRODUCTION.

History 1

Epitome of Anatomy 2

PHYSIOLOGICAL.

CHARYBDEA.

Light and Darkness 5

Concretions 8

Sensory Clubs 9

Velarium and Frenula 11

Pedalia, Interradial Ganglia, Tentacles 12

Stomach, Suspensoria, Proboscis, Subumbrella 13

Margin, Radial Ganglia, Nerve 15

Stimulation 17

Activity of Charybdea 17

Temperature 17

Food and Feeding 18

Occurrence of Charybdea 18

AURELIA AND POLYCLONIA (_Cassiopœa_) 19

SUMMARY 22

DR. CONANT’S NOTES.

CHARYBDEA.

Light and Darkness 24

Sensory Clubs 26

Nerve 29

Side, Subumbrella 30

Pedalia, Velarium, Ganglia 31

Tentacles 32

Proboscis, Stomach, Phacelli 33

Temperature 33

Food and Feeding 33

Occurrence of Charybdea 33

Activity of Charybdea 34

AURELIA AND POLYCLONIA 35

CASSIOPŒA 39

AURELIA 39

HISTOLOGICAL.

Method 40

Anatomy 41

Distal Complex Eye--

General 41

Cornea 42

The Lens 42

The Capsule 44

The Retina 45

(a) The Prism Cells 46

(b) The Pyramid Cells 48

(c) The Long Pigment Cells 50

(d) Subretinal Nerve Tissue 53

(e) Discussion of Literature 53

(f) Function of the Retinal Cells, Patten’s Theory, and
further Literature 56

The Proximal Complex Eye 60

The Simple Eyes 61

Lithocyst and Concretion 63

The Epithelium of the Clubs 64

Network and Multipolar Ganglion Cells 67

The Nerve Tissue 67

The Supporting Lamella 68

Epithelium of Ampulla and Floating Cells 68

The Endothelium of the Peduncle 73

The Tentacles and Pedalia--

The Ectoderm 74

(a) Thread Cells 74

(b) Muscle Fibers 74

(c) Ganglion Cell 75

The Endoderm 75

SUMMARY 77

LITERATURE 78

REFERENCE LETTERS 80

DESCRIPTION OF FIGURES 81