5& o APPENDIX 



chiasma, infundibulum, pituitary body (if not torn away), 

 crura cerebri, spinal cord (Fig. 38, II). 

 9. Examine and draw the skeleton on the following sections : 

 backbone and pelvic girdle in dorsal view (Fig. 10) ; skull, in 

 dorsal (Fig. 10) and in ventral view (Fig. 12) ; hyoid (Fig. 

 16) ; fore-limb (Fig. 10) ; hind-limb (Fig. 10) ; pectoral 

 girdle in ventral view (Fig. 17); pelvic girdle inside view 

 (Fig. 18), and in dorsal view (Fig. 10). 

 10a. Examine a drop of the blood diluted with normal (75) salt 

 solution (Fig. 63, A), 

 b. Tease in normal salt solution a piece of testis. Note sper- 

 matozoa (Fig. 402, B). 



Fig. 402. — A., A diagram of part of a section of the testis of 

 a frog, showing one ripe seminiferous tubule and portions 

 of two others, with connective tissue binding them together, 

 and blood vessels {b.v.). B., A ripe spermatozoon. 



I.C., Cells of the lining epithelium. Some of these are undergoing the 

 divisions by which they form the sperm mother-cells from which in 

 turn spermatozoa arise ; j.c, supporting cells, carrying sp., bundles of 

 spermatozoa. 



1. Examine in normal salt solution the following : pigment cells, 

 in web of foot (Plate III.); striped muscle fibres, frayed 

 apart (Fig. 59) ; unstriped muscle fibres, in wall of bladder 

 spread out (Fig. 58) ; connective tissue, in thin sheet as 

 found among leg muscles (Fig. 61) ; fatty tissue, from fat 

 body (Fig. 62) ; cartilage, from edge of xiphisternum scraped 

 clean (Fig. 60) ; nerve fibres, obtained by fraying out a large 

 nerve with needles (Fig. 55). 



d. Examine the following sections, prepared by an expert : 



bone (Fig. 4) ; nerve (Fig 56) ; spinal cord (Fig. 57) ; in- 

 testine (Figs. 45, 46) ; testis (Fig. 402, A). 



e. Pith a frog (i.e. cut through the backbone just behind skull, and 



pass a seeker through the wound forwards into the skull 



