REFERENCES. 30 1 



belthiere. In Denkschriften der Math.-Naturwiss. Classe der kais. 

 Akad. der Wissenschaften. Bd. XLV. Wien, 1882. 64 pp. 4. 

 Six plates. 



Relates chiefly to nervous system. Describes also the smooth 

 muscle-fibres in wall of pharynx, etc. Finds that the majority of 

 sensory nerve-fibres to the skin end freely between the cells of the 

 ectoderm in bush-like ramifications. For the rest, see NANSEN 

 ROHDE, RETZIUS, and FUSARI. 



55 ROLPH, W. Untersuchungen uber den Ban, des Amphioxus 

 lanceolatus. Morphologisches Jahrbuch, II. 1876. pp. 87-164. 

 Taf. V.-VII. ; also figures in text. 



56 RUCKERT, JOHANNES. Entivickelung der Excretionsorgane. 

 Ergebnisse der Anatomic und Entwicklungsgeschichte (Merkel 

 und Bonnet), I. 1891. pp. 606-695. Includes an extensive bibli- 

 ography. 



57 SCHNEIDER, ANTON. Beitr'dge zur vergleichenden Anatomic 

 und Entwicklungsgeschichte der Wirbelthiere. I. Amphioxus 

 lanceolatus. pp. 3-31. Taf. XIV. -XVI. 4. Berlin, 1879. 



58 SCHULTZ, ALEXANDER. Zur Entwickelungsgeschichte des Sela- 

 chiereies. Archiv. fur Mikr. Anat. XI. 1875. PP- 569-580. 

 Taf. 34- 



Preliminary notes of both Semper and Schultz, regarding the 

 segmental origin of the excretory tubules, were published in the 

 Centralblatt fiir Medicinische Wissenschaft, 1874. 



59 SEMON, RICHARD. Studien ilber den Bauplan des Urogenital- 

 sy stems der II 'irbelthiere ; dargelegt an der Entivickelung dieses 

 Organsystems bei Ichthyophis glutinosus. Jenaische Zeitschrift, 

 XXVI. 1891. pp. 89-203. Taf. I.-XIV. 



60 SPENGEL, J. W. Beitragzur Kenntniss der Kiemen des Amphi- 

 oxus. Zool. Jahrblicher. Abth. fur Morphol. IV. 1890. pp. 257- 

 296. Taf. 17-18. 



61 SPENGEL, J. W. Benhanfs Kritik meiner Angaben uber die 

 Kiemen des Amphioxus. Anat. Anz. VIII. 1893. pp. 762-765. 



62 STIEDA, LUDWIG. Studien uber den Amphioxus lanceolatus. 

 Mem. de TAcad. Imperiale des Sciences de St. Petersbourg, 7th 

 series, Vol. XIX. No. 7. 70 pp. Four plates. 1873. 



Contains some good observations on the central nervous system. 

 First to show that the split-like structure above central canal did 

 not correspond to the posterior fissure of the vertebrate spinal cord, 

 but was a portion of the original central canal itself, the lumen of 

 which had been partially obliterated by approximation of its walls. 

 First identification of ventral (motor) roots of spinal nerves in 

 Amphioxus. 



