xix] 



EMBRYOLOGY 



Fig. 381. Botrychium [Sceptridium) obliquutn. First stages in the embry- 

 ogeny. Before the first segmentation the zygote grows into an elongated 

 tube, cut off later as the suspensor, which burrows its way irregularly 

 into the tissue of the prothallus (xijo). (From sections lent by 

 H. L. Lyon.) 



Fig. 382. Botrychium [Sceptridui/it) obliqmim 

 Muhl. Photo-micrograph of a section through 

 a gametophyte and young sporophyte. The 

 root has already protruded from the under 

 side of the gametophyte. « =archegonium. 

 j' = suspensor, /■= stem-tip, /= first leaf, ;•= rooi 

 ( X 60). (After H. L. Lyon.) 



