ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 379 



appear to be any ground for regarding the " pedes spurii " of cater- 

 pillars as secondary structures ; they are, rather, true embryonic 

 appendages, which were retained in the postembryonic development, and 

 the last pair of which persists through life in the male as the appendices 

 copulatorii. Furthermore, the apparently truly secondary abdominal 

 appendages of the complete insect are of the same morphological signifi- 

 cance, and must be regarded as true homologues of the other extremities. 

 In conclusion, the author refers to the morphology of the larval 

 forms of Insects. The theory of Brauer as to the so-called Campodea- 

 like larvae being the most primitive must be somewhat modified in the 

 light of other researches. The development of Blatta leaves no room 

 for doubt that the insect-embryo is essentially polypodous, and that, 

 consequently, the ancestor of Insects is to be sought for in Myriopod- 

 like forms. Balfour rightly called attention to the similarity between 

 the structure of Peripatus and the organization of lepidopterous larvse. 



Incidental Observations in Pedigree Moth-breeding'.* — Mr. F. 



Merrifield has some interesting notes on the breeding of Moths. The 

 usual difference in size between the spring and the summer emergences 

 appears to be due to the fact that the larva of the former is much longer 

 in feeding up than the latter. The author thinks he has observed that, 

 when there is no stunting or retarding from unhealthy conditions, those 

 larvae of a brood which are longest in feeding up are the largest. 

 Variety in markings and colours, and also in size, is much greater in the 

 summer than in the spring emergence ; some successful experiments have 

 been made in increasing these differences by selection. The application 

 of cold in the earlier stages has a tendency, operating possibly by 

 retardation, to produce or develope a darker hue in the perfect insect ; 

 this may throw some light on the melanism which is so often remarked 

 in north-country examples of widely distributed moths. 



Changes of Internal Organs in Pupa of Milkweed Butterfly,!— 

 Mr. J. H. Emerton has some notes which may be regarded as supple- 

 mentary to the memoirs of Burgess and Scudder on the life- histories of 

 Butterflies. He describes chiefly the earlier pupaa from the time the 

 larval skin is thrown off till the seventh or eighth day. 



Chermes and Phylloxera.^ — Herr L. Dreyfus confirms Blochmann's 

 recent account of the bisexual generation of Chermes ahietis, but the 

 general results of his observations do not agree with those of that 

 author, for he finds that the course of development is much more com- 

 plicated than has been supposed ; indeed it is probable that the cycle is 

 not completed in a single year. He thinks it probable that C. abietis, 

 C Inricis, and C. obtectus are all forms in the developmental cycle of one 

 species. The course of development seems to be as follows: — in the 

 first year G. abietis, having survived the winter, lays eggs ; in the gall 

 on the pine a generation is developed which has wings, and this flies out ; 

 some members of this generation migrate to the larch, where they lay 

 eggs as G. laricis ; the third generation passes the winter on the larch 

 as G. laricis. At the end of April of the second year there is a fourth 

 generation which escapes at the end of May as G. laricis ; the greater 

 number of these return to the pine, where they lay eggs as G. obtectus ; 



* Trans. Entomol. Soc. Lond., 1889, pp. 79-97. 

 t Proc. Boston Soc. Nat. Hist., xxiii. (1888) pp. 457-61 (1 pi ) 

 ■ X Zool. Aazeig., xii. (1889) pp. 65-73, 91-9. 



