xxiv Journal of Comparative Neurology. 



paper consists of critical reviews of previous work. The position of 

 Boll is supported and that of Fritsch is severely handled. A full 

 bibliography accompanies. It is hoped to secure a comprehensive 

 review of this subject for the Journal at an early date. 



The Brain of Limulus. 1 



We are glad at last to announce the appearance of this work for 

 which we have been some time prepared. It forms a bulky quarto 

 with thirty-six plates and numerous figures all elegantly engraved. 

 Viallanes has described the brain of Limulus and given figues of models 

 reconstructed from sections. Kishinyone and Patten have also added 

 embryological data. 



Professor Packard states that the brain is composed of three pairs 

 of lobes, i. e., two pairs of eye-lobes or ganglia, viz. — first those 

 which send nerves to the lateral eyes ; second, those which innervate 

 the median eyes ; and third, the cerebral ganglia, which, with the 

 mushroom bodies, form the chief portion of the brain. The ganglia 

 of the first pair of appendages are separate from the prestomal brain 

 mass and are consequently excluded from consideration with the brain 

 proper. Packard rejects Patten's second pair of median eyes. Vial- 

 lanes' classification of the regions of crustacean and insect brain into 

 three does not apply to Limulus. Viallanes' " protocerebrum " 

 is that which Packard considers the brain proper. 



Packard accepted Viallanes' identification of the so-called nucleo- 

 genous bodies with the pedunculated or mushroom bodies of insects. 

 There is little doubt that the brain is in its general features much like 

 that of Arachnida. The organ described by St. Remy as the "organe 

 stratifie posterieur" in spiders is considered as the homologue of the 

 mushroom body of insects in spite of the fact that it is not double. 

 Two other bodies noted by St. Remy, the ''olivary body" and 

 " organ en bissac" are said by Packard not to occur in the king crab. 



Little embryological matter was added to that published by Kish- 

 inyone and Kingsley. Although many sections were prepared the 

 fine histology is imperfectly made out, owing no doubt to the great 

 difficulty of securing a suitable technique. It is to be hoped that 

 something approaching the methyl blue process may be applied to this 

 subject. 



'Packard, A. S. Further studies on the Brain of Limulus polyphemus 

 with notes on its Embryology. National Academy of Sciences, Memoir 8. 

 Vol. VI. 



