THK VARIOUS MODES OF EMERGKNCE. 105 



of May, S till 25th of May ; second brood, g and ? 28bh of June 

 to 20tb of July ; third brood, ^ and ? Obh of Au.t>URt to 30th of 

 August." It is now evident that in Elba the tardy families of June 

 and July are wanting; therefore there is an interval between the two 

 broods, but the emergence from 28th of June to 20th of July constitutes 

 the " precocious " group of the second brood, separated from the 

 " tardy " group (from the 6th to the 30th of August) by the summer 

 pause ; this apparent brood had led me wrong ; therefore there are 

 only two broods, not three. Tutt, in vol. iv., revised also by Wheeler, 

 of his British Biitter/iies (1914) concludes on p. 215, with the greatest 

 confidence, that irarns at Malta has four, and most probably five, and 

 perhaps even six broods, deducing it from the following observations : 

 " 8th of March, one <? ; a few 3' 3 worn the 26th ; ^ g' common, 

 quite fresh, only one ? seen the 6th of April ; a few worn the 14th 

 April ; the 17th of April one worn J" only ; on 13th of May common 

 and quite fresh ; and on the 15th and 17th common and fresh ; 

 abundant and fresh the 24th of May and the 2nd of June, with some 

 (J (^ of the celina variety, and all 2 ? dark ; the 7th of June com- 

 mon but worn ; the 14th of June abundant and fresh, celina and ? $ 

 of the rufina variety ; on the 18th of August $ g of celina fairly 

 common, but no J J seen ; on the 2nd of October the species still in 

 existence." 



A comparison with Florence reveals instead a surprising resemb- 

 lance of emergence in localities so different in latitude, confirmed 

 by Querci's material from Sicily, where the second brood begins 

 towards June 10th, and shows clearly that also at Malta groups 

 of individuals fly successively much too near each other to 

 constitute broods ; from the 8th of March to the 13ch of May 

 only sporadic precocious individuals appear ; from the 13th of May 

 to the 2nd of June is the " nucleus " of first brood ; about the 

 14th of June commences second brood with characteristic aspect, 

 and its nucleus probably comes on just after August 18th^ The 

 observer does not tell us if the examples from the 2nd of October 

 were old or fresh, but, in any case, they would probably in this last 

 case be the autumnal "precocious" individuals of the spring brood 

 (apparent brood), therefore the six broods of Tutt are reduced to two ! 



It will be observed that the nuclei of the two broods of icartis and 

 of thersites coincide with the appearance of the two of A(/riades thetis ; 

 that of the second at Forte dei Marmi coincides with the third of Aricia 

 viedon.* 



To complete these remarks on graduated emergence I must recall 

 the phenomenon already noted (Bull. 8. E. It., xlvi., p. 113) concern- 

 ing the first brood of Melitaea didyrna, Esp., which consists of a sub- 

 division into two groups, separated by twenty days interval (another 



* I must also mention a phenomenon which I have observed last year (1918) 

 at the Forte dei Marmi, on the Tuscan coast ; in the second half of July males of 

 A. thetis and of Folyornni.atus icarus emerged in great numbers, but not one single 

 female was observed amongst them; in the second half of August the normal, 

 emergence of the females took place, and a good number of males emerged with 

 them, although they were distmctly less abundant than in years in which the 

 July emergence had not occurred, contrasting sharply with the few battered 

 survivors of the July lot. If females had existed in July one might have been 

 tempted to consider the possible existence of three broods. This phenomenon 

 might be called " mono-sexual emergence." — R.V. 



