EVIDENCES OF DESIGN IN REPRODUCTIVE ELEMENTS 159 



PLATE LXIII (continued) 



Fig. 10. — Fertilisation in the plant (Pilularia) as delineated by Campbell. 

 A, B. Early stages in the formation of the spermatozoid. 



C. The mature spermatozoid. The nucleus lies in the spiral turns of the latter at n, a cytoplasmic mass containing starch 

 corpuscles being seen at s. 



D. Archegonium during fertilisation. In the centre, the ovum (o) contains the apposed germ nuclei (g, n). Shows spherical, 

 concentric, segmented, and spiral arrangements. 



Fig. 11. — Spermatogonium of Salamander as figured by Driiner. n, Nucleus; a, enormous aster, its rays giving indications of 

 nine concentric circles of microsomes ; c, centrosome, or centre of force, from which the rays of the astei- diverge, and round which 

 the circles ot microsomes arrange themselves. Affords an outstanding example of radiating and concentric ariangenients. 



Fig. 12. — Germinal cells of Volvox as figured by Overton. 



A. Spermatozoid. cv, Contractile vacuoles ; e, eye spot (chromoplastid) ; p, pyrenoid. 



B. Spermatozoid stained to show nucleus (n). 



C. Ovum (oosphere) with large central nucleus (n), and peripheral layer of ehroniatnphores. p, Pyrenoid. Shows spherical, 

 concentric, and branching arrangements. 



Figs. 13 and 14. — Germinal \'esicles of eggs, showing chromosomes, tetrads, and nucleoli. 



Fig. 13. — Cyclops xtrenunx, illiistrating Hacker's account of the tetrad formation from elongated doulile rods with group of 

 accessory nucleoli (Hacker). 



Fig. 14. — Germinal vesicle of an annelid (Ophryotrocha), showing nucleolus («'), four chromosomes (c, r, c, c), and asters (a, a'), 

 according to Korschelt. Shows spherical, concentric, and radiating arrangements. 



Fig. 15. — Living ovarian egg of an insect, water-beetle (Dytiscus), iV} figured by Korschelt. The egg {ov) lies between two 

 groups of nutritive cells ; the germinal vesicle sending amo'boid processes into the dark mass of food-granules. 



Fig. 16. — Egg and nurse-cell of the annelid (Ophryotrocha) in the young stage, as depicted by Korschelt. In this condition the 

 nurse-cell (m) is considerably larger than the egg (o). As the ovum grows the egg becomes larger and the nurse-cell smaller — the 

 latter ultimately shrivelling up. The egg practically lives on the nurse-cell so long as it lasts. 



Fig. 17. — Mitosis in the flagellate (Noctiluca), early prophase (Ishikawa). n, Nucleus ; s, attraction-sphere ; c, two centro- 

 somes. 



PLATE LXIV 



Plate Ixiv. illustrates globular, radiating, concentric, branched, segmented, and spiral arrangements, especially 

 the latter (spiral) in the sexual elements. 



Fig. 1. — Spermatozoids of plants. A to D as given by Guignard, and E to F as given by Strasburger. 



A. Of an alga (Fucus) ; B. Liverwort (Pellia) ; C. Moss (Sphagnum) ; D. Fern (Angiopteris) ; E. Marsilia ; F. Fern (Phegopteris). 

 In A, a red chromatophore occurs at the right of the nucleus, and at F, the nucleus is coloured dark. Illustrates spiral, branching, 

 and spherical arrangements. 



Fig. 2. — Unusual form of spermatozoa. 



A, B, C. Living amceboid spermatozoa of the Crustacean (Polyphemus), as figured by Zacharias. D, E. Spermatozoa of crab 

 (Dromia); F, of Ethusa; G, of Maja ; and H, of Inachus as given by Grobben. I, of Lobster (J?oma)-K.<!)— Herrick ; and J, of 

 crab (Parcellana)—Qrohheu. Illustrates radiating, concentric, and branching arrangements. 



Fig. 3.— Diagram of a flagellate spermatozoon. The spermatozoon has been divided to economise space (Wilson), a, Apex or 

 apical body; n, nucleus; ek, end knob (? centrosome); mp, middle piece; et, envelope of tail; af, axial filament; ep, end 

 piece. 



Fig. 4.— Spermatozoa of fishes and amphibia as given by Ballowitz. 



A. Sturgeon; B. Pike; C, D. Leuciscus ; E. Triton (anterior part); F. Triton (posterior part of flagellum) ; G. Raja (anterior 

 part), a, Apical body; e, end piece; /, flagellum; k, end knob (? centrosome); m, middle piece; n, nucleus. Illustrates spiral 

 and waved arrangements as witnessed in swimming and serpentine movements. 



Fig. 5.— Spermatozoa of various animals (after Ballowitz, Von Brunn, and Wilson). 



A. Bird (Phyllopneuste) ; B. Bird (Muscicapa) ; nucleus divided into two parts (,i ', n "), no distinct middle piece ;C. Bullfinch 

 with spiral membrane; D. Giant form of spermatozoon of the sheldrake (Tadorna); E. (lull (Innts), with spiral middle piece and 

 apical knob. Illustrates spiral and waved arrangements. 



Fig. 6. — Spermatozoa of mammals (after Ballowitz and Wilson). 



A. Badger (living); B. The same dead and after staining; C. Bat (Vesperugo) ; D. The same, flagellum and middle piece 

 showing end knobs ; E. Opossum (after staining) ; F. Rat ; G. Head of spermatozoon of pig ; H. Head of the spermatozoon of the 

 bat (Rhinolophus) showing details ; I. Double spermatozoon from the vas deferens of the opossum. he, Head cup (apex) ; k, end 

 knob (? centrosome) ; m, middle piece ; »., nucleus (in B, H, and G, consisting of two parts) 



Figs. 4, 5, and 6 illustrate in a striking manner the spiral and waved arrangements which obtain in spermatozoa as a class. 



