( 112 ) 



V. On the Protocerebrum of Micropteryx (Lepidopiera). 

 By P. A. Buxton, B.A., F.E.S., M.R.C.S., Fellow 

 of Trinity College, Cambridge (Lieut. E.A.M.C). 



[Read February 7th, 1917.] 



Plates VII-X. 



Table of Contents. 



Foreword ...... 



Introduction ...... 



The Protocerebrum of Micropteryx — 



I. The Neurilemma and Ganglion Cells 

 II. The Protocerebral Lobes 



III. The Mushroom Body . 



IV. The Central Body 

 V. The Bridge 



VI. The Visual Centres 

 VII. The Protocerebral Tracts . 



Summary ..... 



Technique — 



I. Fixation and Impregnation . 

 II. Section Cutting . 



III. Staining .... 



IV. Note (Composition of Reagents) 



Bibliography 



Abbreviations .... 



Explanation of Plates . 



PAGE 



112 

 114 



118 

 120 

 124 

 133 

 134 

 135 

 136 



138 



141 

 145 

 146 

 148 



149 

 151 

 152 



FOREWORD 



More than four years ago I commenced to study the 

 internal anatomy of Micropteryx {Eriocephala) in the hope 

 that I might be able to throw some Hght on the question of 

 its systematic position. As is well known, most entomo- 

 logists regard it as a primitive Lepidopteron (Protolepido- 

 ptera), though there is really quite as good ground for 

 regarding it as a Trichopteron.* I am now in a position 

 to publish my results only in so far as they relate to a 

 portion of the brain of that insect. This I do with a feeling 



* Vide, however, Dr. Chapman's paper (Trans. Ent. Soc, 1916. 

 pp. 310-4, pi. 81-93, (1917)), which raises Micropteryx to ordinal 

 rank (order Zeugoplera). 



TRANS. ENT. SOC. LOND. 1917. — PART I. (NOV.) 



