Volume TV 
DECEMBEK, 1911 
No. 4 
THE LIFE-HISTORY OF PLEI8T0PH0RA GIGANTEA, 
THELOHAN {GLUGEA GIGANTEA THEL.). 
By K H. SWELLENGREBEL, Ph.D. 
{From the Hygienic Institute, Uiiiversity of Amsterdam.) 
With Plates XVII and XVIII and 20 Diagrams. 
CONTENTS. 
PAGE 
1. 
Introduction ........ 
34.5 
2. 
Materia! 
and methods ....... 
346 
3. 
Description of the life-history of P. gigantea ; . 
346 
(a) 
The Trophozoites ....... 
348 
(G 
Formation of the pansporoblasts .... 
349 
(c) 
Formation of the sporoblasts .... 
355 
(d) 
Formation of the spores ..... 
358 
ie) 
Diffuse infiltration ....... 
360 
(f) 
Eeaction of the host’s tissue against the parasitic 
invasion ........ 
360 
Summary .......... 
362 
1. Introduction. 
Among the Neosporidia the Microsporidia constitute a group dis¬ 
tinguished from the allied Myxosporidia by the small size and simple 
structure of the spores. A full account of the literature on this subject 
is to be found in the excellent papers of Thelohan (1895), Stempell (1909), 
Schuberg (1910), etc. 
According to 'Minchin’s system (1903) the Microsporidia are divided 
into: 
(1) Polysporogenea, the trophozoite {i.e. the vegetative stage of the 
life-cycle) produces many pansporoblasts, containing many spores. 
Parasitology iv 
23 
