PLATE IV. 



This Plate is chiefly devoted to illustrations of the various forms of Reproduction among Rhizofoda generally, 

 and to representations of the sarcode-bodies of Orbitolites and Polystomella. 



Fig. 

 1.- 



10.— 



11. 



1:2.- 



13.. 

 11.. 



Portion of the body of an OrbitoUtes of the 

 complex type, in which the sarcode has 

 broken up into spherules ; a, a, superficial 

 segments j b, b, part of the annular stolon : 

 180 diam. 



■Peculiar bodies (gemmules or ova ?) found in the 

 substance of different parts of the sarcode- 

 body of OrbitoUtes, showing successive stages 

 a, b, c, d, e, f, of binary subdivision ; ff, other 

 bodies of somewhat larger size, found in one 

 of the superficial chamberlets of a vertical 

 section : 130 diam. 



■Rotalia, whose sarcode-body has dark spherules 

 imbedded in it. (After Schultze.) 



•Reproduction of a triloculine Miliola ; a, parent 

 giving off young ; b, one of the young, more 

 highly magnified. (After Schultze.) 



•Decalcified specimen of Truncatulina ; a, a, mem- 

 branous basis of shell ; b, sarcode ; c, c, c, c, 

 ova (?) with germinal vesicles and germinal 

 spots ; d, d, two segments destitute of ova. 

 (After Wright.) 



■Amceba radiosa, with its nucleus (a) beginning to 

 enlarge and become granular, preparatory to 

 the development of sperm-cells. (After Carter.) 



-One of the sperm-cells of Amwba radiosa, more 

 highly magnified, in its actinophorous stage, 

 previously to the hardening of the pellicle and 

 the development of the spermatic granules. 

 (After Carter.) 



■Ammba verrucosa, of which the body is converted 

 into an ovisac filled with granuliferous germ- 

 cells. (After Carter.) 



-Euglyjjha alveolata, in the interior of which have 

 been evolved from the nucleus delicate granu- 

 liferous sperm-cells. (After Carter.) 



Euglyplia alveolata, of which the body is con- 

 verted into an ovisac filled with germ-cells. 

 (After Carter.) 



EuDlypha alveolata, in which sperm-cells (a) and 

 germ-cells (b) are developed within the same 

 test J c, supernumerary scales. (After Carter.) 



Portion of the sarcode-body a, a, of a Poti/sto- 

 niella, extruded by pressure from the fractured 

 shell; b,b, detached spheroids of the same; c, 

 another detached spheroid beginning to put 

 forth pseudopodial extensions resembling those 

 of a, a. (After Schultze.) 



Nuclear (?) bodies imbedded in the sarcode of 

 Gromia. (After Schultze.) 



Entire sarcode-body of an OrbitoUtes of the 

 simple type, the shell having been removed by 

 maceration in dilute acid ; in the peripheral 

 portion the segments of the sarcode-body 

 are wanting, and the structureless basis of the 

 shell is alone seen : 40 diam. 



Kg. 



15 — 20. — Central portions of the sarcode-bodies of 

 OrbitoUtes, showing varieties of the mode in 

 which the first annulus originates from the 

 circumambient segment ; a, primordial seg- 

 ment ; b, b' , circumambient segment ; c, seg- 

 ments of first annulus; d, peduncle connecting 

 primordial with circumambient segment ; e, e, 

 peduncles connecting circumambient segment 

 with first annulus : 84 diam. 



21. — Central portion of the disk of an OrbitoUtes of 

 the simple type, showing an abnormal com- 

 mencement of growth. 



22. — Pi'imitive disks produced by a large OrbitoUtes 

 of complex type, as seen at a on one of their 

 lateral surfaces, and at b edgewise, showing 

 the marginal pores. 



23. — Part of the peripheral portion of Fig. 14 enlarged, 

 to show the ordinary mode in which the seg- 

 ments c, c, of each zone are connected by 

 radiating peduncles e, e, with the annular 

 stolon h, h, of the preceding zone, so as to 

 alternate with its segments ; showing also the 

 occasional interpolation of additional segments 

 c" , c" , whose peduncles, e , e , come off from 

 the segments of the preceding zone : 90 diam. 



24. — Portion of one of the superficial strata of the 

 sarcode-body of an OrbitoUtes of complex type, 

 as seen from above ; aa' , a a' , a a , zones of 

 superficial segments, connected at their two 

 extremities with the annular stolons bb' , bb : 

 150 diam. 



25. — Portion of the sarcode-bod}' of OrbitoUtes of com- 

 plex type, as seen in vertical plane ; a a, a a' , 

 upper and lower rows of superficial segments, 

 each connected at its two extremities with the 

 annular stolons b b, and b' b' , of two zones; 

 the annular stolons b b, b b, connect the ex- 

 tremities of the columnar segments c, c, c, c, 

 which occasionally inosculate with each other, 

 and which conimuuicate with the iilternating 

 columns c', c , of the zone behind (whose ex- 

 tremities are in like manner connected by the 

 annular stolons V b') by rows of oblique pedun- 

 cles alternately passing towards one side and 

 the other : 150 diam. (n.b. This figure is 

 somewhat ideal, being made up from several 

 preparations ; but for every point which it 

 represents, these preparations give warranty.) 



26. — Disk of OrbitoUtes repaired after fracture ; a, a, 

 the new zone by whose extension around the 

 broken margin the reparation has been 

 effected : 35 diam. 



27.- — ^Disk of OrbitoUtes reproduced from a detached 

 fragment ; a, a, the zone from which the re- 

 paration seems to have proceeded : 35 diam. 



28. — Sarcode-body of the animal of Polystomella 

 crispa, showing at a, a, a its segments, and 

 at b, b their retral processes. (After William- 

 son.) 



