52 REPORT— 1872. 



that species is least in proportional quantity. This is true of crustacean 

 life as well as that of other forms ; and I think it worthy of consideration, 

 particularly by those who, as a crucial test in the theory of evolution, demand 

 the exposition of a series of successional forms of life ; they should remember 

 that of the lobster, common as it is around our coasts and in our markets, 

 there is not a fisherman or observant naturalist who has yet seen that 

 stage in its life which unites the animal as we know it with that which we 

 have seen it when it quits the egg ; that is, no one has seen or knows any 

 thing about the animal between the time when it is half an inch and the time 

 when it is four inches in length. That which is true of the lobster, is like- 

 wise true of all .the higher forms of Crustacea, excepting only that of the 

 common littoral or shore-crab ( Carcimts mcenas). 



The second circumstance that I wish to notice is one that has been eluci- 

 dated by obseiTation in the aquarium. I have several times observed that a 

 specimen of Pagurus, or soldier crab, will seize hold of the shell in which 

 another, generally smaller, specimen of the same species is dwelling. I 

 supposed that the larger animal was covetous of the shell in which the 

 smaller dwelt. I have seen them, as I thought, endeavour to take posses- 

 sion of such occupied shell, until their soft and tender body received such a 

 pinch from the previous possessor as compelled them hastily to retrace their 

 steps. 



Mr. Alford Lloyd has written in my note-book the following sentence : — 

 " In the spring of the year, in the Hamburg Aquarium, I have seen the male 

 of this crab take hold of the shell in which a female is contained, and carry 

 her about for weeks together, grasping the thin edge of her shell (as of a 

 Buccinum) ; and when the female is led the male does not take awaj' the 

 food, as he would if a male were so fed in his vicinity." 



I would here like to state that the preservation of Crustacea by keeping 

 them in glycerine for a few days, and then drying them, will be found to be 

 a very superior plan to that of spreading them out without any preparation. 

 I have specimens that have been treated two or three years with glycerine 

 that are as flexible as a fresh crab. It will be better of course that as much 

 of the soft parts should be removed as possible. I have also been trying, 

 and I think with success, to preserve fish in the same way. A specimen of the 

 Bogue (Spants hoops, L.), taken more than two months ago, is as fresh in colour 

 and as flexible as when captured, excepting the eye, which was in a partially 

 decomposed state when jjlaced in the glycerine. I think, when further experi- 

 ments have confirmed the fact, that with or without admixture with another 

 medium, glycerine may afford a very valuable addition to the preservative 

 agents of our museums. 



Among the MoUusca we have to record the capture of many specimens of 



Eledone . This has generally been supposed to be a rare species ou 



our coast ; but we find that Octopus vulgaris, the supposed common species, 

 is the more difficult to obtain. Both these appear to live well and happily 

 in captivity ; so also does Sepia officinalis. 



Mr. Rogers, who has charge of the pond at Plymouth, and is a most active 

 and zealous collector of marine animals, tells me that two specimens of this 

 last-named cuttlefish were placed in the pond on the 8th of June, 1871 . 

 They continued doing well until the 24th, when they were seen to be in 

 copuM, head to head, arms interlaced, and remaining stationarj-, resting on 

 the bottom for about twelve minutes, then separating. On the 26th the 

 male was killed by a dog, which seized it when in shallow water. These 

 creatures were rarely seen far apart, usually following each other in every 



