NOV 26 1906 
The Ohio £J\Naturalist, 
PUBLISHED BY 
The Biological Club of ihe Ohio State University. 
Volume VII. NOVEMBER. 1906. No. 1. 
TABLE OF CONTENTS 
Schaffner. Mabel —The Embryology of the Shepherd’s Purse. 1 
Bruner— Some Guatemalan Orthoptera, with Descriptions of Five New Species. 9 
Caudf.li. —List of Orthoptera Collected in Guatemala by ('. C. Deam andE. B. Williamson 14 
Hambi.eton— Key to the Families of Ohio Lichens. 14 
JIcCleery—P ubescence and Other External Peculiarities of Ohio Plants. 16 
News and Notes . . 18 
Hyde—M eeting of the Biological Club. 18 
THE EMBRYOLOGY OF THE SHEPHERD’S PURSE* 
(A Posthumous Paper.) 
Mabel Schaffner. 
The embryo of the shepherd’s purse (Bursa bursa-pastoris 
(L.) Britt.) has had an important place as a representative dieotyl 
in most botanical textbooks. The original investigations of 
Hanstein (1) and Famintzin (2) were superior and epoch-making 
for their day, yet many points were left obscure and some of 
these are still unsettled, as a reference to the various botanical 
textbooks will show. Considerable variation has been reported 
as to the succession of the cell divisions and other minor details. 
The best recent account is by Coulter and Chamberlain (4, 5), 
and what is given below is practically a confirmation of their re¬ 
port with a few differences in details. 
The embryology of Alyssum as given by Miss Riddle (3) 
shows several interesting deviations from the Bursa type and 
makes it clear that generalizations can not be made without full 
knowledge even in the case of closely related plants. 
It was my intention to make a complete study of the embrvo 
of Bursa and to prepare a series of drawings on the same scale 
of magnification in order that not only the succession of cell divi¬ 
sions and the development of the several embryonic tissues would 
be apparent but also the actual increase in size of the embryo as 
a whole and of the cells at various stages of development. 
The ordinary methods of killing and imbedding were emploved 
and the serial sections, cut 10-12 mic. thick, were stained on the 
slide. Delafield’s haematoxylin makes a very satisfactory stain 
if properly employed. 
* Contributions from the Botanical Laboratory of the Ohio State 
University, XXV. 
