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The Museum Gazette 



alone. In the collection at South Kensington there are three 

 varieties of blue cuckoo's eggs which were laid in the nests of 

 the hedge sparrow, redstart, and pied flycatcher, all of which 

 lay blue eggs ! 



" The young cuckoo has a depression in the back, which 

 gives a more secure lodgment to the young bird or egg it 

 wishes to eject, and the back is broad considering the size of 

 the bird." 



On Abnormal Shells. 



We quote the following interesting observations from Dr. 



Chaster's presidential address, at the last annual meeting of 



the Conchological Society (October, 1906) : — 



" The various deviations from the normal that are produced by direct 

 injury or by disease are worthy of mention. These we may perhaps 

 call pathological. In the case of some long, slender shells the apex has 

 so frequently and for so many generations been subjected to injury, 

 that at length the species has acquired the habit of making prepara- 

 tion for it. In Turritellce, for example, the apical one-fourth or so of 

 the shell will be found to be unoccupied by the animal, which has 

 shut off the upper whorls by a series of successive septa occurring 

 about every half-turn. In Truncatella and other forms the process is 

 carried still further, for, before the septum is made, the shell about to 

 be vacated is so thinned that it is soon broken off and the adult is 

 always decollated." 



Potato Disease. 

 There are some interesting notes on Phytophthora infestans in 

 the seventh issue of the Kew Bulletin for last year. " Experi- 

 ments prove that tubers can only be infected during the earliest 

 stage of growth ; when the tuber has reached the size of a 

 marble and a definite periderm or skin is formed it is free 

 from danger. Judged from a morphological standpoint, the 

 relationship of the fungus causing 'leaf-curl' to that of another 

 fungus — Mdcrospenum tomato, Cooke, parasitic on cultivated 

 tomatoes — was some years ago indicated as follows : ' This 

 fungus is closely allied to if not identical with, the Macro- 

 sporium causing black stripe or blotch on the tomato ' (' Text- 

 book of Plant Diseases,' p. 323). Inoculation experiments 

 have proved this supposition to be correct. Conidia produced 



