96 



Mr. E. R. Lankester. 



[June 15, 



Dr. Packard observes — " These glands are quite large and apparently 

 of some physiological importance, and are easily found, as they are 

 conspicuous from their bright red colour, causing them to contrast 

 decidedly with the dark masses of the liver, and the yellowish 

 ovaries or greenish testes, near which they are situated. The glands 

 are bilaterally symmetrical, one situated on each side of the pro- 

 ventricle and stomach, and each is entirely separated from its fellow. 

 Each gland consists of a stolon-like mass extending along close to the 

 great collective vein, and attached to it by irregular bands of con- 

 nective tissue, which also hold the gland in place. From this hori- 

 zontal mass four vertical branches arise, and lie between and next to 

 the partitions at the base of the legs, which divide the latero- sternal 

 region of the cephalothorax into compartments. The posterior of 

 these four vertical lobes accompanies the middle hepatic vein from its 

 origin from the great collective vein, and is sent off: opposite the 

 insertion of the fifth pair of feet. Halfway between the origin of the 

 vein and the articulation of the limb to the body, it turns at a right 

 angle, the ends of the two other lobes passing a little beyond it, and 

 ends in a blind sac, less vertical than the others, slightly ascending at 

 the end, which lies just above the insertion of the second pair of feet. 

 The two middle lobes are directed to the collective vein. Each lobe 

 is somewhat flattened out, and lies close to the posterior wall of the 

 compartment in which it is situated, as if wedged in between the 

 wall and the muscles between it and the anterior portion of the com- 

 partment. Each lobe also accompanies the bases of the first four 

 tegumentary nerves." 



I can fully confirm the accuracy of this careful description of the 

 naked-eye appearance and situation of these glands. I am also in 

 agreement with Dr. Packard, when he states that these glands have 

 no opening into the great veins, and, like him, I have as yet been 

 unable to detect the situation of their opening to the exterior. 



Dr. Packard's description of the minute structure of these brick- 

 red bodies is such as to have led me to doubt the correctness of his 

 conclusion that they are glands and more especially renal glands. At 

 the time when I wrote to that effect I had only made dissections 

 showing their position and relations in two specimens of Limulus. I 

 have since been able to obtain perfectly fresh specimens of the brick- 

 red glands from a Limulus killed for the purpose, and having 

 hardened them in absolute alcohol, I have prepared and examined 

 sections demonstrating their minute structure. 



This does not agree with the description given by Dr. Packard, 

 whose account of the minute structure of these bodies led me to 

 doubt their glandular nature. 



Dr. Packard states that ' ' the four lobes end in blind sacs and have 

 no lumen or central cavity," and in the next paragraph somewhat 



