6 Wisconsin Academy of Sciences, Arts, and Letters. 
cells of the prothallium and those of the outgrowth. Farlow 
describes tracheids extending back from this cell mass into 
the vegetative tissues of the prothallium. The first leaf grows 
out on the anterior side of this projection. Then the first root 
forms and after this the stem apex is organized on the upper 
side of the base of the first leaf. The three organs, leaf, root 
and stem form successively, and there is no foot. 
Apogamy has since been found in many different groups of 
ferns and the list of these is still being increased. 
In 1878 De Bary (5) gave a more detailed account of the 
“Farlow shoots” in Pteris cretica. De Bary describes the apoga- 
mous outgrowth as beginning as a group of three or four cells 
just back of the marginal meristem at the apical notch. A 
mass of cells is formed by growth and division and at the apex 
of this mass an apical cell is differentiated and through its 
activities the first leaf develops. In the rounded angle between 
the upper surface of the leaf base and the prothallium a shal¬ 
low protuberance—the stem Anlage—is formed. It soon be¬ 
comes clothed with hairs and later a second leaf forms. The 
boundary between gametophytic and sporophytic tissue is ob¬ 
scure. The vascular bundle runs down the leaf stalk and into 
the prothallial tissue. Ventral to the vascular bundle, and 
usually near the first leaf insertion, a root is formed endo¬ 
genously which pushes out and grows down into the ground. 
The root may form in the prothallium considerably below the 
leaf insertion when the vascular bundle reaches that far. 
De Bary found that with the formation of the sporophyte 
the prothallium ceases growth. In case no sporophyte is pro¬ 
duced on a prothallium it gives rise to secondary or adventive 
prothallia. Occasionally a sporophyte forms on a secondary 
pro thallium. 
In addition to the “normal” Farlow shoots, various anomalies 
are found. There may be two “first” leaves with a stem 
Anlage between them. The first two roots may appear simuh 
taneously. There may be two apogamous outgrowths, one on 
the dorsal and one on the ventral surface of the prothallium. 
The leaf may be as usual while the stem Anlage is on the dor¬ 
sal side of the prothallium. When the sporophyte aborts, a 
