146 PROFESSOR E. RAY LANKESTER. 



Gegenbaur notices that these ligaments are elastic, and 

 resist the action of reagents. 



6. Lakge-celled (Embryonic) connective tissue of Scorpio. 



In some regions, especially around the large pro-somatic 

 ganglion in Scorpion, groups of cells, of oval or nearly spherical 

 form, with abundant finely granular protoplasm, and often with 

 two nuclei, indicating an active condition of multiplication, are 

 found. They correspond in character to the little groups of 

 proliferating cells above-mentioned as occurring in connection 

 with the membranous connective tissue, but are numerous, and 

 form a distinct tissue. 



In these groups of cells (PI. XI, fig. 9) we have the con- 

 nective tissue reduced to a simple embryonic form. There is 

 no skeletal substance developed around the protoplasm of the 

 cells, but simply the protoplasmic units free from any special 

 product of chemical metamorphosis. Possibly this tissue is 

 concerned iu the production of blood-corpuscles. Its cells are 

 evidently in a high state of proliferous activity and closely 

 resemble blood-corpuscles. It is possible to trace a gradation 

 from the surrounding lacunar tissue to this large-celled tissue 

 devoid of matrix or other ectoplastic product and equally 

 devoid of any entoplastic product. The gradation is exhibited 

 in the reduction of the capsular element of the lacunar tissue 

 and the enlargement and close-setting of the protoplasmic 

 cells (PI. XI, fig. 10), until at last we find spots in which no 

 capsular (skeletal or matrix product) is present at all and the 

 protoplasmic cells are massed together in simple contact. The 

 term ' embryonic ' is appropriate to this tissue since at an early 

 period when the special skeletal products of the connective 

 tissue have not come into existence, it consists of indiiferent 

 embryonic cells packed side by side as in these small tracts 

 surrounding the great nerve-ganglion. Here and there in 

 other parts small quantities of this tissue are found. I have 

 not observed this tissue in Liraulus. 



