KUNGL. SV. VET. AKADEMIENS BANDLINOAR. HAND 56 no I 



::< 



Patten (1893 — 94) hat die Embryonalentvvicklung der Globuli behandelt. Er 

 sagt: »From the verv start each hemisphere shows a distinct separation into two 

 lobes — a poslerior one, drawn out into long sharp points, and an anterior lateral lobe. 

 Both lobes are separated from each other by a deep fissure, in the angle of which 

 lies the slender fibrous peduncle on which the hemisphere is supported. The shape 

 of the hemispheres in the second larval stage is accurately shown in fig. 47. The 

 fore-brain region is drawn from a wax-plate model, the rest from dissected specimens. 



<jloj,A. 



dl.a**Z v. 



Textfig. 9. Gehirn von Limulus von oben. Rekonstruktionsbild. — Ant. eom. = Antennalkommissur. Fr. Lob. = 



Frontallobe. Oz ra = medialer Ozellarnerv. St B = Stiel des Globulus B. Stv B A = Stielverbindung des Globulus A. 



StvB B = Stielverbindung des Globulus B. StvB C = Stielverbindung des Globulus C. 



Obrige Bezeichnungen wie auf Toxtfig. 8. 



The posterior lobes are not so slender and pointed as at an earlier stage, and both 

 lobes show the first traces of the convolutions so characteristic of the brain at a 

 låter period. The hemispheres have united with each other along the median line, 

 and the anterior lateral lobe is beginning to grow around on to the under side of 

 the brain. Two cross-sections of the brain in this stage are shown, one through 

 about the middle of the hemispheres, another, farther back, showing the growth of 

 the lobes över the rest of the brain. A third cerebral lobe, the median internal lobe 



K. Sv. Vet. Ältad. Handl. Band 56. N:o 1 10 



