Vol. 35 



No. 7 



BULLETIN 



OF THE 



TORREY BOTANICAL CLUB 



JULY, 1908 



The development of the sexual organs and sporogonium of 



Marchantia polymorpha* 



elias j. durand 

 (with plates 21-25) 



For some time past the writer has been preparing sets of slides 



for the use of students in a course in embryology. The aim has 



been to get together series as complete as possible to illustrate the 



important steps in the development of at least one representative 



of each of the great groups of green plants. The slides when 



•wished are numbered, and each valuable section on the slide is 



marked and numbered. The stages represented are then care- 



y arranged in sequence and outlines prepared in which they are 



■ndicated in their proper order with the numbers of the slides and 



sections in which they appear. In this way the student, having 



a d all the sections found, marked, and arranged for him, and hav- 



g to waste no time in searching for the desired stages, can study 



maximum amount of material in the minimum of time. 



" should be emphasized that such slides are not intended to 



a e the P lace of but to supplement those which the student makes 



° r hlms elf in order to get training in the methods used in the 



Preparation of such material. It will be readily understood that 



get together series of this kind requires much time and patience, 



J* ^e writer feels that the outlay is fully justified by the results 



a 'ned. The student who goes over a set of preparations such 



B illustrated in the present paper, making drawings of all the 



£ e s, and finally writing up for himself an account of the devel- 



j^ en toLthejjlant based on his own studies and drawings has at 



[Th °" lnbution from the Department of Botany, Cornell University, no. 131. 

 6 ButLET lN for June, 1908 (35 : 283-320.//. 18-20) was issued 1 Jl 1908.] 



321 



