1896.] The Life-History of Sequoia. 335 
the sporangium become enclosed in a subconical cavity, the 
micropyle. About the time when the micropyle begins to 
close, the hypodermal tissue of two opposite sides of the in- 
tegument begins to grow in a radial direction to form the 
wings of the seed. In some cases the thickening of the in- 
tegument occurs on three or four sides, in the directions of 
least resistance, but only two wings are developed. About 
the middle of February, when the micropyle has closed, the 
hypodermal cells in that part of the integument which sur- 
rounds it develop thick pitted walls which appear to be ligni- 
fed (fig. 5, e). Upto this time the sporangium has grown 
slowly and it now begins to elongate by growth of the cha- 
zal portion (fig. 3). The seed reaches its full length and 
width in June, when it is about 5°" wide by 6°" long. 
In December the sporangium is cylindrical in form and 
about as long as broad, and surrounded by the integument 
which reaches about to the same level. Within the epidermis 
ae five to seven central longitudinal rows of cells surrounded 
by one or two layers of smaller cells which are also arranged 
longitudinal rows. Each of the central rows of cells ap- 
ears to have originated in a single cell immediately beneath 
the epidermis, and the rows extend from the apex of the 
‘porangium nearly to the chalaza, in which no regular ar- 
In the earliest 
tells (fig. 1). Later stages show several cells in each row, 
Which the innermost, larger and longitu 
dermis at the micropyle (fig. 3, 4) 
© apex of the sporangium (figs. 4, ¢ and 5, ¢)- 
Middle of March eh aes mb about the base of the 
