8pong. 1 
XVII. SPONGLE. 
BY 
W. Woodland. 
CONTENTS. 
Page 
Introduction 3 
I. Titles 4 
II. Biology ...... .... 8 
a. Evolution . 8 
b. Morphology 8 
(i) General Accounts 8 
(ii) External Characters 8 
(iii) Anatomy of Soft Parts. Canal-System . . 8 
(iv) Skeletal System 8 
(a) General Accounts 8 
(b) Material of the Skeleton .... 9 
(c) Skeletal Elements, Morphology, Develop- 
ment, and Nomenclature of . 9 
(d) Skeletal Anatomy 9 
(v) XHistology 9 
(a) General Accounts 9 
(b) Special Organs or Tissues ... 9 
c. Physiology 9 
(i) General Accounts 9 
(ii) Particular Functions 9 
d. Bionomics 10 
e. Reproduction, Development and Growth ... 10 
(i) Germ-Cells, Fertilization 10 
(ii) Embryology 10 
(a) General Accounts 10 
(b) Early Stages, Larvae, Metamorphosis, &c. 10 
(iii) Asexual Reproduction ...... 10 
(a) Fission, Vegetative Budding and Regene- 
ration 10 
(b) Germinal Budding and Gemmule-For- 
mation 10 
