Protocerehrum of Micro pteryx. 149 



who have tried this stain give conflicting accounts of its 

 vaUie is due to the fact that there is no standard composi- 

 tion for it. Mallorifs hrematoxylin. — The stain consists 

 of hsematoxylin crystals 1 gm. ; chloral hydrate 10 gms. ; 

 10 % solution of phosphomolybdic acid in water 1 c.c. ; 

 distilled water 100 c.c. The sections are mordanted in 

 5 % copper sulphate solution for twenty-four hours, washed 

 in tap water, placed for \ or -|- hour in the stain diluted 

 with four times its volume of distilled water, rinsed and 

 carefully decolorised in a solution of sodium bicarbonate 

 in distilled water. Bretschneider's application of Mallory's 

 anilin blue, with some slight modifications of my own, is as 

 follows : Delafield's haematoxyl 1 hour, or until the nuclei 

 are faintly stained ; wash ; eosin twenty minutes ; wash in 

 water; 1 % phosphomolybdic acid two minutes. Mallory's 

 stain one minute; wash, dehydrate and mount. The com- 

 position of the Mallory's stain is anilin blue (water-soluble) 

 |- gm., orange Gr (water-soluble) 2 gms., oxalic acid 2 gms., 

 distilled water 100 c.c. Mannas stain ; 1 % aqueous sol. 

 methyl blue 35 c.c, 1 % aqueous eosin 35 c.c, water 100 c.c 

 Stain ten minutes or longer, for it is impossible to overstain, 

 and then wash in alcohol containing 1 % of pyridin, watch- 

 ing the process of decolorisation mider the microscope; 

 with practice the right degree of decolorisation can easily 

 be obtained. 



Bibliography. 



A very complete bibliography is given by Kiihnle. It 

 is only necessary for me to give a list of the authors and 

 papers to which I have referred. 



A. Works dealing with the Segmentation of the Arthro- 

 pod Head, etc. 



Brauer, a. (1) 1894. Beitrage zur Kentniss der En- 



twicklungsgeschichte des Skorpions. Part 



I. Zeitschr. f. wiss. Zool., Bd. LVII. 



(2)1895. Ditto. Part II. Op. cit., Bd. LVIX. 



Heymons, R. (1) 1895. Die Embryonalentwicklung von 



Dermapteren und Orthopteren. Jena 



(Fischer). 



(2) 1897. Entwicklungsgeschichtliche Un- 

 tersuchungen an Lepisma saccharina. 

 Zeitschr. f. wiss. Zool., Bd. LXII. 



(3) 1901. Entw. gesch. der Scolopender. 

 Zoologica (Chun.), XIII. 



