Miscellaneous. Ill 



as follows ill my previous paper : — " Most of them were pretty 

 severely crushed, in part even mutilated. Some, however, on being 

 brought into a warm room, soon so far recovered again that no 

 injury whatever could be perceived." This is not quite correct. In 

 the year 1888 Dr. Doderlein informed me that his attention also 

 had been drawn by an agriculturalist near Strassburg to the winter 

 supplies of the mole. He stated that examination revealed the fact 

 that the first segment of all the worms was severely injured, so that 

 they could not burrow. A new investigation of my own completely 

 confirmed this statement. In all the specimens the first segment 

 was injured, aud often several others besides. It is true that in 

 many instances the wounds were already almost completely cica- 

 trized ; the most recently captured individuals were, however, still 

 bleeding. The worms were therefore prevented from escaping not 

 only through being securely imprisoned within the walls of the 

 dwelling-chamber and passages, but also through this highly practical 

 mutilation, and were nevertheless jDreserved alive. The crushings, 

 which, as I stated previously, are not always present, are probably 

 to be regarded as of a secondary nature, and result from the worms 

 being jDressed into the walls. — Zoologischer Anzevjer, Jahrg. xiv. 

 no. 353, Jan. 5, 1891. 



On the Development of the Chromatophores of Octopod Cephalopoda. 

 By L. JouBiN^. 



The anatomical structure of the chromatophores of adult Cepha- 

 lopoda is now tolerably well understood, and the theory which 

 attributed the movements of the pigmented matter to contractions 

 of muscular fibres appears to be definitely abandoned ; but people 

 are far from being agreed as to the mode of development of these 

 organs. Having had the opportunity of studjing the cmbryogeny 

 of Ar(/onauta and Octopus at Banyuls, I have arrived at results 

 ■which apj)ear to me to be very different from what was found to be 

 the case in the Decapod Cephalopoda. 



Contrary to the opinion of M. Girod, who regards the chromato- 

 phores of the Decapoda as developing at the expense of the meso- 

 derm, contrary, too, to the belief of M. Phisalix, who considers the 

 pigmented cell of Sepiola as resulting from the fusion of a number 

 of other cells, I hold that the chromatophore of the Octopod is of 

 ectodermic origin, and that its accessory parts alone are mesodermic. 

 This is tolerably comparable to what is found in the organs of 

 sense. 



In the embryo of Argovavta the integument consists of a simple 

 ectodermic epithelium covering a loose mesodermic connective 

 tissue. 



In the dorsal region enclosed between tlie two eyes we observe, 

 better than anywhere else, certain scattered ectodermic cells 

 becoming larger than those surrounding them, then, little by little, 

 sinking down into a sort of depression shaped like a funnel, 

 dragging the neighbouring cells with them. 



