56 SCIENCE PROGRESS 



" The Genesis of the Organisation of the Insect Egg : II. Inter- 

 action of Nucleoplasm and Cytoplasm " (ibid. Dec. 191 7). 

 By a detailed investigation of the internal structure and 

 relations of the egg of beetles the author is led to the conclusion 

 that at the time of fertilisation the ovum is a mosaic of different 

 cytoplasmic units each predetermined to produce definite 

 parts of the embryo. This complex results from the inter- 

 action of nucleus and cytoplasm which is particularly noticeable 

 during such periods of activity as the extrusion of chromidia. 

 The importance of such studies will be realised when we con- 

 sider the many cases where the cytoplasm controls even the 

 behaviour of the chromatin. 



Other papers include : " Descriptions of New Pyralidae 

 of the Sub-families Hydrocampince, Scopariance, etc." (Ann. 

 and Mag. Nat. Hist. Oct. 191 7) and " Descriptions of New 

 Pyralidse of the Sub-family Pyraustince" (ibid. Nov. 191 7), 

 both by Hampson ; " New Species and Forms of Sphingidae," 

 by Joicey and Kaye (ibid. Oct. 191 7) ; " New Indo-Malayan 

 Lepidoptera," by Swinhoe (ibid. Nov. 191 7) ; " New South 

 American Rhopalocera," " New South American Arctiidae," 

 " New Butterflies from Africa and the East," " Gynandromorph 

 of Papilio lycophron," and " Three Aberrations of Lepidoptera," 

 all by Joicey and Talbot (Proc. Zool. Soc. Nov. 191 7) ; and 

 " Notes on a Collection of Heterocera made by Mr. W. Feather 

 in British East Africa," by Fawcett (ibid.). 



11 The Structure, Bionomics, and Forest Importance of 

 Myelophilus minor, Hart," is the subject of a paper by Ritchie 

 (Trans. Roy. Soc. Edin. vol. lii. Dec. 191 7). Two species of 

 Myelophilus are indigenous to Britain and well known to the 

 forester. The present note is an anatomical and bionomic 

 study of the less known of these. They are very destructive 

 to pine plantations in all stages, feeding on the young shoots 

 and boring into the stem for breeding purposes. It appears 

 to be confined to the Scots Pine, though on the Continent it 

 attacks other trees, but luckily enough in Scotland it is only 

 able to pass through one generation in a year. However, it 

 is possible for the same parents to have two broods in the year 

 after an interval during which the reproductive organs recover 

 their activity. To some extent the pest can be controlled 

 by arranging trap trees in the plantation. 



Other papers include : " Contributions to the Knowledge 



