LABOBArORr STUDIES OF CRYPTOGAMS 165 



tion. Good preparations of the arcliegnnin, fi-om wliicli the spoi'ogonia 

 originate, are more difficult to make. If time allows, vertical sections 

 of the young archegonial heads may be made by tlie pupils; or better, 

 the aichegonia may be drawn from preparations provided by the 

 teacher. Distinguish the central egii cell, the neck and canal. 



386 (Simple). Moss. — Select a single plant, in fruit. Draw the 

 habit as seen with the hand lens. Examine with the highest power 

 of the dissecting microscope. Is there distinction of leaf and stem? 

 Are the leaves petioled? Have they midribs? AV^itli needles clear 

 away the leaves at the point where the stalk of the spore capsule 

 {apnrogoniinn) originates. Does this stalk spring from the end of a 

 shoot of the nross, or is it a branch springing directly from the side of 

 a shoot? Is there any appearance of a joint or any mark around the 

 base of the stalk? Are the shoot and stalk separable? 



387 (Simple). Look for a cajisule which still bears on its summit 

 a loose cap, tlie cnli/ptra. Draw the capsule, niuch enlarged. Remove 

 the calyptra. Examine tiie now exposed end of the capsule with a 

 strong lens. Do you hnd any appearance of a lid, or cover, by the 

 removal of which the capsule may be opened? Draw the outlines (jf 

 this part of the capsule, labeling the lid operculum. Slight pressui'i; 

 may force the latter off. Teeth standing within the edge of the open- 

 ing majf be seen. Note the quantity and appearance of the spores. 



388 (Compound). AVith the compound microscope examine the 

 protonemn of the moss, if this is provided, and draw a portion. Look 

 for buds, or beginnings of new leafy shoots. 



389 (Simple or Compound). If ready mounted sections of the 

 flower, so called, are provided, the iircJiei/iDiia and iinlheriilin nuiy be 

 studied under the teacher's direction. At least, the shoot tips bea,ring 

 these organs should be examined \\itli a lens, and then dissected care- 

 fully with needles in a little water under the dissecting lens. By 

 skillfully removing the leaves that form moi'e oi' less of a rosette 

 around the desired parts, and by farther separation if necessarj^ 

 archegonia and antheridia may be distinctly seen, together with the 

 sterile filaments, or paraphyses, that grow up with them on the end of 

 the stem. 



390 (Simple). Fern. — 1. The protludlium. Place a young prothal- 

 liiini on the stage of the dissecting microscope, without water. Ex- 

 amine rapidly with the lens. Are the upper and under surfaces alike? 

 Is the prothalliuin of equ.al thickness throughout? By what means is 

 the plant attached to the .soil? Add water. If soil particles still ad- 

 here, remove carefully with a small wet brush or with needles. The 

 general form reminds you of what cryptoganions plant before studied? 

 In what respects (refer to former drawings)? Which is the younger 

 extremity of the prothallium? 



Turn it under side upwards and view by transmitted light. Draw 



