BRACHYURI. 177 



if specimens are causally brought ashore, they are always so maltreated, 

 that I caunot affirm I have ever witnessed their survivauce for any 

 length of time, to bring the roe to maturity. Therefore, it is chiefly 

 from younger individuals that we can look for satisfactory results. 



As the ovarium swells, the anxiety of the parent for its preservation 

 from injury, becomes very evident. When elevating the apron or breast- 

 plate, it is kept free of external pressure, by the creature continually 

 standing on the Umbs, and rising higher and higher to avoid contact 

 with other substances below. 



Hence, it will be observed, that the capsules are not deposited, but 

 burst like the former, while attached to the parent, for escape of the 

 young. These are of the wonted form, resemble the preceding, nor are 

 distinguished by any pecuharities. 



The crab-fishery seems to be neither a lucrative nor a favourite em- 

 ployment in Scotland ; and, although many are occupied in it, chiefly 

 on a small scale, it appears to be alwaj^s deserted when other branches 

 of such marine pursuits occur. 



Plate XXXVIII. 



Fig. 1. Cancer pagurus, the Common Crab, back. 



2. The same, breast. 



3. Cluster of ova, natural size. 



4. Portion of the same enlarged. 



5. Portion more enlarged. 



Plate XXXIX. History of a white specimen. 



Fig. J. Cancer jMgurus, young, taken 29th September. 



2. The same, after its first exuviation in captivity, on November 9. 



3. The same, after exuviation on April 30, following November 9. 



4. The same, after a third exuviation, on September 12. Back. 



5. The same. Breast. 



6. The same, after a fourth exuviation on March 29, following Nov. 12, 



when the whole eight legs proved deficient. Back. 



7. The same, shewing the deficiency. Breast. 



8. The same, after a fifth exuviation on June 23, when all the parts 



were restored entire. Back 



