Protocerebrum of Micropteryx. 151 



ViALLANES. (1) 1886. Le Cerveau de la Giiepe. Ann. 

 de Sci. Nat. Zool., Ser. VII, Tome II. 

 (2) 1887. Etudes histologiques et organo- 

 logiques sur les centres nerveux. V"®. 

 Memoire. Le Cerveau du Criquet (Oedi- 

 poda and Caloptenus). Ann. de Sci. Nat. 

 Zool., Ser. VII, Tome IV. 

 ZiEGLER, H.E. 1912. Die Gehirne der Insecten. Naturw. 

 Wochenscbr., Bd. XI. 



Abbreviations Used. 



In every case the same abbreviations are used in the 

 Plates as in the text figures. 



The letters a, b, c, d, etc., refer in all cases to tracts. 



a, h, c, d, etc. (p. 136). 



as. br. = ascending branch (= forward root) of mushroom 



body. 

 a.s. = axonic substance ^ fibrillar substance. 

 as. tr. = ascending trunk of mushroom body. 

 br. = bridge. 

 br. hd. = head of bridge. 

 d. I. = dorsal lobe of protocerebrum. 

 dm. — deuterocerebrum (= antennary lobe). 

 d. sy. = deuterocerebral or paired sympathetic system. 

 ei. = Einstrommung (see p. 120). 

 g. c. = ganglion cells of the " normal " type. 

 gi. c. = giant cells. 

 hd. = head of mushroom body. 

 in. ca. = inner capsule of central body. 

 in. r. = inner root of mushroom body. 

 1. 1. =^ lateral protocerebral lobes. 

 Zo. = " la loge " of Viallanes. 

 vib. = mushroom body. 

 nib. c. = cells of mushroom body. 

 mi. I. = middle lobe. 

 mi. I. a. and mi. I. p. = anterior and posterior portions of 



middle lobe. 

 mm. = tract mm., (p. 138). 

 7)10. n. = motor antennary nerve. 

 ng. = nuclei of neuroglia cells. 

 nl. = neurilemma. 

 nn. — nuclei of the neurilemma. 



