58 E. LÖNNBERG, ON THE CEPHALOPODS. 



densely woven together so that the niass is very tough to 

 tear to pieces with tlie dissecting needles; the cell-membranes 

 too might be elastic. The nuclei of this tissue are small, 

 often attached to the fibrils when these are isolated. On 

 tangential sections the cellmembranes are better conspicuous 

 and the tissue resembles, to a certain degree, a section through 

 the parenchym of some plant (Fig. 2). Through the central 

 mass of the papillse bloodvessels are seen to brauch, and also 

 nerves of a comparatively large size. At the periphery of 

 the papillse I have seen on some sections what apparently is 

 transversally cut muscles. There exists thus peripherical or 

 circular muscles which may serve to regulate the tension of 

 the papilla and when they contract they diminish the tangen- 

 tial diameter of the same, but extend it in radial direction. 

 The interspaces between the papillse vary in width 

 from 2 to V 2 mm. These interspaces are filled by a very 

 delicate tissue, but this is mostly destroyed. On sections. I 

 have however been able to see the structure of some parts 

 which still remain. It resembles very much the tissue I 

 have described in the aboral part of the »terminal papilla» in 

 Spirula reticulata. 1 It is a connective tissue consisting of 

 large, usually oval or ellipsoidal cellules imbedded in a richly 

 developed gelatinous matrix. The nuclei are rieh with chro- 

 matin and very darkly stained. The matrix is seldom (juite 

 homogenous but shows itself nearly always (that is in the 

 parts which are left and which have been most resistent) 

 supported by a network of very fine fibrils. But in some 

 places these fibrils become stronger and gradually pass over 

 into the common fibrous tissue. In some places the cellules 

 lie dose together without any matrix and then constitute 

 fat corpuscles (Fig. 3). It is probable that a great deal of the 

 destroyed tissue has been fat tissue because one gets oily only 

 by touching the animal. The tissue in the interspaces between 

 the papilla thus is a composition of a gelatinous connective 

 tissue and a kind of »blubber». First outside of all these 

 layers of different tissues we find the integument or skin 

 covering the body and itself consisting of connective tissue, 

 muscles running in various directions in different strata, the 

 chromatophors and the epithel (Fig, 1, sk.). 



' -Notes on Spirula reticulata», 1 Festskrift für Lilljeborg» Upsala 1896 

 p. 109. 



