author's abstract op this paper issued 

 by the bibliographic service, june 27 



THE HISTOGENESIS OF DENSE LYMPHATIC TISSUE 

 OF THE INTESTINE (LEPUS) : A CONTRIBUTION TO 

 THE KNOWLEDGE OF THE DEVELOPMENT OF 

 LYMPHATIC TISSUE AND BLOOD-CELL FORMATION 



JOHN STEPHENS LATTA 



Department of Histology and Embryology, Cornell University, Ithaca, New York 



FOUR PLATES (SIXTEEN FIGURES) 



CONTENTS 



Introduction 159 



Historical 160 



Materials and methods 161 



Lymphopoiesis 165 



Granulopoiesis 182 



Erythropoiesis 189 



Discussion of relations, etc 196 



Summary 198 



INTRODUCTION 



The origin, development, and fate of the various cellular ele- 

 ments of the blood, their relation to the loose connective tissue 

 of the body, and the conditions associated with, or causing their 

 production, are still unsettled and debatable questions despite 

 the vast amount of previous investigation of hematological prob- 

 lems. 



Some of the most perplexing of these problems arise in dis- 

 cussion of the production of lymphatic tissue, or lymphopoiesis, 

 as found in various places in the body, more particularly in the 

 tonsils of the mouth and intestine. Just what are the conditions 

 which bring about or are associated with the formation of lympha- 

 tic tissue? Are these conditions controlling its formation the 

 same, wherever it occurs, e.g., in the tonsils as in the lymphatic 

 nodes? Or are there different conditions, the presence of any 

 one of which may initiate and control lymphopoiesis? Does 

 lymphopoiesis, wherever occurring in the body, always serve the 



159 



