304 PROCEEDINGS OF THE ACADEMY OF [1887. 



by H. Miiller^ from the peculiar contents of the glandular cells as 

 observed by him. 



As set forth at length in a former communication to this Academy' 

 I was unable in any of my specimens to find in the oesophagus or 

 stomach of Salpa the large plasmodium described by Koratnefi".* 

 I have serial sections from many specimens showing the entire curve 

 of the alimentary canal from the mouth to the rectum in which the 

 lumen throughout is perfectly free from any organized protoplasmic 

 mass. Other preparations show the food laden mucus passing from 

 the branchial cavity through the pharynx, oesophagus and stomach. 

 Before reaching the stomach, on account of its containing much 

 protoplasmic material which has not yet been acted upon by the di- 

 gestive juices, this mixture of food and mucus takes staining very 

 well ; but after reaching the stomach it gradually refuses to stain, 

 and in the intestine consists of a mass of colorless debris, owing to 

 the organic materials having been removed by digestion. Sections 

 cut diagonally across the oesophagus sometimes appear as though 

 the lumen of the tube was almost obliterated except a narrow slit 

 on one side, this is not actually the case as sections cut longitudi- 

 nally (fig. 9.) or at right angles prove. 



My observations opposed to the presence of an inter-cellular or 

 parenchymatous digestion in Salpa, referred to above, have since 

 been confirmed by Oswald Seeliger* in his interesting and valuable 

 paper on the budding of Salpa, in which he refers to this subject as 

 follows : "Ich muss demgegeniiber nun darauf aufmerksam machen, 

 dass Korotneff im Magen von Salpa africana Verhiiltnisse angetroffen 

 hat, die darauf schliessen lassen, dass in denselben thatsiichlich 

 Nahrung hineingelangt und daselbst verdaut oder resorbirt wird. 

 Ich habe leider Koratneff''s Angaben iiber die "freien Magenzellen" 

 und die "parenchymatose Erniihrung" der Tunikaten nicht an ver- 

 schiedenen Objekten nachstudiren konnen, bei Salpa democratica 

 aber fand ich sie nicht zutreffeud. Audi von anderer Seite (Dolley) 



1 Heinricli MuUer, Ueber die anatoniische Veischiedenheit der zwei For- 

 men bei den Salpen. Ztschr. f. wiss. Zool., Bd. IV. 1853, p. 330. 



^ "Some observations op])osed to the presence of a parenchymatous or intra- 

 cellular digestion in Salpa." April 15th 1884 vid. Proceedings, Acad. Nat. Sci. 

 Philadelphia. Zool. Anz. 1884, p. 705. 



^ Dr. A. Koratneff. Ueber der Knospung der Anchinia. in Ztschr. f. wiss. 

 Zool. Bd. 40. Hft. 1, 1884, Feb. 19. 



* Oswald Seeliger. "Die Knospung der Salpen" Jenaiscbe Zeitschr. fur 

 Naturwissenschaft," Bd. 19, page 631. 



