176 Prof. M'Intosh's Notes from the 



annelid crawled actively amongst the ascidians and other 

 growths to escape capture. 



This form clearly approaches Genetyllis lutea, Malmgren, 

 but the setigerous region supported by a black spine and 

 carrying shorter bristles with shorter terminal processes than 

 in that species point to separation. 



5. On the Reproduction o/" Nereis diversicolor, 0. F, Miiller. 



Various statements have been made about the reproduction 

 of this species. Thus Max Schultze * refers to the occur- 

 rence of the young in tlie body-cavity, having apparently 

 considered Koch's statements in regard to Marphysa sanguinea 

 as true. 



Cuvier and Grube, again, thought Arenicola was herma- 

 phrodite, and Rathke placed Amphitrite in the same category, 

 though each might be more or less male or female. An 

 interesting resume of the views of the period is given by 

 Fiey and Leuckartf. A. Krohn, again, describes from Nice 

 a viviparous 8ylUs {S. vivi'para) allied to S. Armandi, only 

 the new form has simple tips to the terminal pieces of the 

 bristles. The enclosed young form has 23 segments and is 

 like the adult. 



In Balfour's ' Embryology 'J it is stated that " a few 

 forms (e. g., Eunice sanguinea, Syllis vivipara, and Nereis 

 diversicolor) are viviparous." Considerable reliance in more 

 recent times has been placed on the observations of Mendthal 

 on the supposed hemaphroditism of Nei-eis diversicolor. This 

 author seems to have been attracted to the subject by the 

 ))revious work of Schroder §, who found embryos in the 

 niorula-stage. Mendthal described the species from the bay 

 of Pillau as carrj-ing both eggs and testes in June, and he 

 was the more inclined to believe in its hermaphroditism since 

 Schroder met with only 3 males out of 48 examples. He 

 places and figures the testes in the dorsal region as pear- or 

 flask-shaped masses to the exterior of the dorsal longitudinal 

 muscles. The supposed testes, therefore, occupy the same 

 position as the outer limb of Dr. Goodrich's dorsal organ, and 

 it may be that the cilia were a source of misapprehension. 

 On the other hand, he describes the ova as developing at the 

 bases of the feet, the figure representing them in the position 

 of the segmental organ. 



* ' Entwickelung Arenicola piscatorum Sec.,' p. 214 (Halle, 1856). 



t Beitr. z. Kenntniss wirb. Thiere, p. 82 (1847). 



X Vol. i. p. 319. 



§ This author's paper has not yet been obtainable. 



