PLATE 4 



EXPLANATION OF FIGUKES 



A to E Gryllotalpa borealis, side views, metaphase plates of the first sper- 

 matocyte division, showing the single unpaired chromosome and the chroma- 

 toid body. 



F, G, H, I Gryllotalpa vulgaris, Naples. F, an oogonial cell with mito- 

 chondria. G, H, I, Stages in the growth period showing migration of mito- 

 chondria out into the cytoplasm. 



J Pyrrhocoris apterus, first spermatocyte division, late anaphase, showing 

 the marked difference in the appearance and arrangement of the mitochondria 

 when compared with Gryllotalpa. 



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