ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 60* 



that the removal of the coloured parts does not prove that colour has 

 no influence in attracting insect visitors. " We are fond of attributing 

 great intelligence and power of perception to the bee, and yet in this 

 case the insect is not even given credit for being able to recognise what 

 are known to it, from possibly long experience, as the essential parts of 

 the flower ! Because we buy well advertised goods, and still continue 

 to buy them when their proved virtue renders advertisement a thing of 

 the past, is it proof that the advertisement played no part in determining 

 our choice ? " After citing some of Lord Avebury's experiments, Mr. 

 Lowe suggests that the correct method of settling the question would 

 be to cut away, not the petals, but the stamens, &c. " Then if insects, 

 continued to visit flowers so mutilated we should have ground for 

 thinking that petals exercise some attraction, or vice versa.'''' 



Dimorphic Spermatozoa in Butterflies.* — D. N. Voinov finds that 

 in Golias, Papitio, Macroglossa, and Vanessa a twofold spermatogenesis 

 is normal. From similar spermatogonia, there arise two sizes of sperma- 

 tocytes, as in Paludina and Pyyrera (Meves) and in Scolopendra (Bouin).. 

 The large spermatocytes show regular mitoses, the small spermatocytes 

 divide somewhat irregularly. The result is bundles of large and of 

 small spermatozoa, differing only in size. 



What is the interpretation ? Are the small spermatozoa non-repro- 

 ductive, failures in short ? Are the two kinds physiologically equivalent ?' 

 Or does the dimorphism play a part in the determination of sex ? 



Precocious Development of Pupal and Imaginal Organs in 

 Caterpillars.f — H. Kolbe describes a very interesting case of an ab- 

 normal caterpillar of Dendrolimus pini (= Lasiocampa or Gasiropacha 

 pini. The caterpillar had passed its third moult and had already attained 

 to an approximation to the imaginal conditions as regards antenna^ 

 maxillas, and limbs. The formative discs of the subsequent wings were- 

 seen under the skin. The abnormal form represents a stage in the 

 series of metamorphoses which no longer exists normally. Some more 

 or less similar cases of precocity in development, in- Melanippe motanata 

 (E. H. Jones), in Sericaria mori (C. Majoli) and in Tenebrio molitor 

 (Heymons) are referred to. 



Male Genital Appendages in Lepidoptera.J — E. Zander has made 

 an elaborate study of these. He finds, from his investigations on 

 Paraponyx stratiotaria, &c, that the male genital appendages in Lepido- 

 ptera arise from primordia morphologically the same as those in Hymeno- 

 ptera and Trichoptera. The homology is manifested in four ways : — 

 in the formation of a post-segmental insinking of the ventral region of 

 the twelfth segment, forming the genital pouch ; in the appearance of a 

 pair of simple primitive papillae at the base of this pouch ; in the secon- 

 dary splitting of each papilla into a lateral piece (valva) and a median 

 piece (penis) ; and in the origin of the penis from originally paired 

 components. 



But the subsequent history of the genital pouch and the pair of. 



* Arch. Zool. Exper., -1th ser., i. (1903); Notes et Eevue, pp. xlix.-lii. 



t SIS. (*es. Naturf. Berlin, 1902, pp. 158-Go. 



% Zeitschr. wiss. Zool., lxxiv. (1903) pp. 557-615 (1 pi. and 15 figs.). 



Oct. 21st, 100 J -2 k 



