34 THE entomologist's uecord. 



A second brood raised from eggs laid by the moths produced from 

 the four larvie of the first brood, to which alhxsion has ah-eady been 

 made (the grand fnlighiosa form), yiekled 1 Forward, several Uoubtfuls, 

 o30 Normals, but no Laggards. 



A fourth brood, raised in June, was the only one that formed any 

 exception to the rule that Forwards were as rare as in earlier l)roods. 

 When the brood was four weeks old, a census showed that it was then 

 composed of 7G Forwards: 12 in 6th, 51 in 6th, and 18 in 7th skin ; 85 

 Normals : 35 in 4th, 46 in 5th, and four in 6th skin ; 49 Laggards : 

 three in 2nd, two in 3rd, and 44 in 4th skin. In this brood it was very 

 difficult to divide the larvae into groui)s, for there was a regular grada- 

 tion of forms between the 3 Laggards in 2nd skin at one extreme, 

 and the 13 Forwards in adult plumage at the other. The brood no 

 doubt liad the benefit of a slightly higher temperature. 



Of a sixtli l)rood, some were kept warmer than the rest and yielded 

 15 Forwards and 34 Normals ; of which 14 were larger and 20 smaller 

 hybernators ; the remainder, 232 in numljer, presented 15 Forwards, 

 79 Intermediates, 44 larger and 85 smaller Normals, and 9 Ijaggards. 

 Many of them became unhealthy, either from inbreeding, domesticaticm, 

 or want of care, and the experiment was allowed to terminate. The 

 differentiation of the liybernators into a larger and a smaller form was 

 very marked in the later broods, and was usuall}', but not always, 

 associated with the hybernation of the larger form in 6th skin. 



Althougli a tabulation of forms is, owing to their great numl)er and 

 to their frequently passing into one another, difficult to make either 

 complete or intelligible, yet a tabulation of the princi})al and most 

 distinct forms may be useful. 



Forwards. — 1. Passes from 4tli (Sjyilosoma) to 5tli (cain), omitting 

 fuh'ginosa i)lumage, feeds up rapidly, and does not 

 hybernate. 



a. Adult in 6th skin. 



b. Adult in 7th skin. 



Normals. — 2. Fullyinosa plumage in 5th skin, in which it hybernates ; 

 cam plumage in 6th skin. 

 II. Adult in 7th skin. 

 h. Adult in 8th skin. 



3. Larger Form ; more profound hybernation. 



4. Assumes /«//;//« os« plumage in 6th skin after hyber- 



nation ; adult in 8th and 9th skins. 



5. Assumes fMliijiuona plumage and hyl)ernates in 6th 



skin. 

 Laggards. — 6. Feeds slowly, never assumes distinct /«//;///( os(/ 2'hiii^<^ge; 

 reaches caia i:)lumage in 8th and 9th skins. 

 7. j\Iany variations, in which hybernation takes place in 

 6th, 7th, 8th, or 9th skins, and either in Jhliyiuosa 

 or in caia plumage. 



I liave several times taken " Laggards " at large ; i.e., larvae ap- 

 parently in the plumage of the 3rd or 4t]i skin, found in Sej)tend)er or 

 October, and that feed on slowly and do not go into fulii/inosa plumage, 

 nor attempt to hybernate. It is therefore certain that, though in 

 England the gi*eat mass of caia larvte is of what I liave called the Nor- 

 mal form, that is, the form whicli is speciallj' well clothed in the 5th 



