166 LABORATOnr STi'DIES OF CRVPTOGAMS 



the outline ( x :Vri) ; mark the margin at (lie bottom of the cliief notch 

 as the i/ruiriiii/ jioinl. linlieate l>y shailing iu tlie pi'oper place any 

 thickened I'oi'tion, and murk this cushion. Show the root hairs, or 

 rhizoids. 



391 (Compound or Simple). Anlheriilia. Small prothallia should 

 show the antheridia plainly under the simple lens, especially if the 

 (living) material is first treated with aqueous iodine for two or three 

 minutes and then washed. The antlieridia are seen as small round, 

 browu bodies. Indicate their position and relative size on the draw- 

 ing already made. AVitli the compound microscope the general 

 structure of these organs can be made out probabl}' without section- 

 ing. an<l a drawing may be made. 



392 (Compound or Simple). Archer/onia. Older prothallia maj' be 

 required. Treat with iodine, as before. With a low power the pres- 

 ence and distribution of the archegonia (appearing as numerous short 

 columns of cells projecting fiom the cusliion) may be made out. In 

 many of the older and over-i'ipe archegonia a central cell, embedded 

 in the prothallium at the base of the projecting neck, is seen as an 

 opaque, brownish sphere. Indicate the position and numljer of the 

 archegonia on the diagram liefore drawn. 



The details ui struct lire will require higher powers and sections of 

 the prolliallinm, either providi-d already mounted, or made under the 

 teacher's directions. 



393 (Simple). -. Oi-njin of llie .fpore-heitriiig plant. From the ma^ 

 terial [ii'ovided find out from what part of the prothallium the leafy 

 shoot springs. Is tliere a motV and if so, does it originate from the 

 tissue of the prothallium or from the new shoot? Answer these ques- 

 tions in a drawing (x --1). 



394 (Sini[>li;). '■]. Tlie .yjnres. Examine a "fruiting" leaf of tlie 

 matun- plant. Are the "fruit spots" (sori, sing, .sv*™.^-) on the upper 

 or under side? Have they a definite location upon the divisions of 

 the leaf? Imlicate the facts in an outline .sketch. Pick off a leaf 

 segment and placing it on the dissecting stage under the lens, with 

 needles carefully raise the covering (inrluslum) of a sorus. Estimate 

 the number of spore casrs (.yjoraiu/in) found beneath. Have they 

 stalks? If you liave no liigli-power instrument, draw, highly niagni- 

 hed, all the details you can discern with the simple microscope. 

 JIuch can be made out in this way. Draw (1) the sorus covered by 

 the indiisium (if present). (■_') the group of sporangia uncovered. 



395 (Compound). If high powers are at hand, further examine 

 sporangia anl spores, after removing from the leaf with a knife point 

 and mounting in water in the usual way. 



396 (Simpli-)- Selaginella. — With hand lens examine the arrange- 

 ment and shai.es of the leaves, and di'aw a short secti(.>n of the shoot 

 ( X 3— i) to show these points. Do the shoots of Selaginella grow 



