16-2 LABORATORY STUDIES OF CRYPTOGAMS 



some cases these bi-anches (^anlheridia) may send tubes into the 

 oogonia. The antheridia may giow fiom the stalks of the oogonia 

 themselves, or from the main hyphci^ close by. 



Draw old and young oogonia, with contents, and antheridia (if 

 found ).' 



372 (Simpli-). Peziza. Upon what as a siibstratnui does the spe- 

 cies of Peziza furnished grow? If the Peziza is small, use the hand 

 lens in examination. "What is the general shape? Is the external 

 surface entirely smooth ? Is the color the same on inner and outer 

 surfaces? Represent all features of form in a drawing considerably 

 larger than nature, if necessary. 



373 (Compound). Cut sections perpendicular to the inner sur- 

 face. Mount in water. Do you find, with a bigli power, elongated 

 sacs containing a definite number of rounded bodies (spores)? Do 

 you find many or few such sacs? (If tlie sections are not vei'y thin, 

 press the cover glass down cautiously with a needle to spread them out 

 thinner.) How are they situated relatively to one another and to the 

 surface of the plant? They are near which surface, inner or outer? 

 How many spores in each sac, or a.icu.'i? Draw a diagram of the Peziza 

 in section, showing the region of the sacs, and indicate some of ihe 

 sacs in position. Draw a sac (aseus) highly magnified, with spores, 

 a'_id the th)-e;uls that grow up between the sacs. 



374 (Compound). Pulling off with forceps bits of the substratum 

 at the I'oint where the cup of the Peziza was attached, and spreading 

 tliese bits out with needles in water on a slide, you may find the 

 threads of the fungus, which gather nourishment from decayed vege- 

 table matter. These threads together form tlie inijcelium ; the sau- 

 cer-shaped or cn[vshaped sac-bearing body first examined is the 

 apotliecinm. That layer of the apothecium in which the sacs are 

 found is the hijinenium. Label drawings according to tlie terms given. 



375 (Simple). MicrosphcEra.- With the lens examine the whit- 

 ened ])atches of the fungiLs-infested leaf. Is the whitening external 

 or internal? To decide this, wet the leaf with a drop of alcohol, and 

 scrape gently with a knife point. The black, rounded bodies are 

 periilifrid. Indicate by drawing the size of the leaf and of the peri- 

 thecia. AVet a bit of the fungus with alcohol, and remove with a 

 kuite to water on a slide. If the material has been dried, add strong 

 potash solution to the preparation. Is the white film composed of 

 granules or of threads? Examine the perithecia by transmitted 

 light. Have they appendages? Draw a perithecium much magni- 



' In the same mount more than one kind of Water Jlold may bie 

 found, the species differing in position and character of oogonia, and in 

 antheridia and .sporangia. 



^ I ir any eeiuis cif the .croup Eripipherr ; perhaps ilie commonest form 

 tjeing JIirri:riph<i:ra nlni. Ilie cause of nnldew iin Lilac leaves. 



