2628 Journal of Applied Microscopy 



CURRENT BOTANICAL LITERATURE. 



CHARLES J. CHAMBERLAIN, University of Chicago. 



Books for Review and Separates of Papers on Botanical Subjects sJiould be Sent to Charles J. 

 Chamberlain, University of Chicago, Chicago, 111. 



ih 



Parkhurst, H. E. Trees, Shrubs, and Vines of This book presupposes no previous 

 the Northeastern United States. 8vo. pp. knowledge of botany, but is intended 



4i;i. Illustrated. Charles Scribner's Sons. , .1 4- „ i„ ^ u„ ;.^i,^., 4-^ 



Z? ^r ^ ^ r> ■ *, ,-^ lor the nature lover who wishes to 



New York, 1903. Price, #1.50. 



become acquainted with the trees, 

 shrubs, and vines without the labor of a preliminary training in botanical science. 

 Even in the descriptions, very few technical terms are used, and these are fully 

 explained and illustrated. While the book is addressed to the non-botanical 

 public, the keys cannot fail to be useful to the botanist as well, for in scientific 

 works the keys are based so largely upon the details of floral structures that 

 they are of little value except during the short flowering season. The keys of 

 this book are based upon the leaf and other features of growth, and consequently 

 are useful for fully half the year. The figures of leaves are very numerous and 

 are very accurately drawn. 



Considerable space is devoted to the trees, shrubs, and vines of Central Park 

 in New York. This feature, however, is not one of mere local interest, for a 

 survey of the list of forms in this park shows that it includes practically all of the 

 plants which are likely to be met in any part of the northeastern United States. 



The book can be recommended heartily to nature lovers, whether they live in 

 the city or in the country. c. j. c. 



Tischler, Q. Ueber Embryosack-Obliteration While it is well known that the pollen 



bei Bastardpflangen. Beihefte zum Bo- ^f sterile hybrids is often imperfect, 

 tanischen Centralblatt, IS : 408-420, pi. 5, .,,.,., 



1003. comparatively little is known about the 



behavior of this embryosac in these 

 forms. The present paper deals with the embryo sac of Rihes Gordonianu7n 

 Lem., a hybrid between R. ai/reufji Pursh and R. saiiguineum Pursh, and with 

 the embryo sac of Syringa chinensis, a hybrid between 6". vulgaris and S. persiea. 

 Both parents of Rihes Go> doniaiium have normal embryosacs with conspicuous 

 nutritive tissue in the chalazal region of the ovule. In the hybrid, this nutritive 

 tissue is lacking and the development of the embryosac is usually checked long 

 before it reaches the fertilization period, the megaspores often failing to germi- 

 nate at all. 



In the parents of Syringa chinensis the nutritive tissue is in the form of a 

 jacket surrounding the embryosac, which, in both cases, is normally developed. 

 In the hybrid the nutritive jacket is more highly developed than in the parents, 

 but the embryosac becomes disorganized quite early, so that the stage at which 

 fertilization might occur is seldom or never reached. 



References are given to the few instances previously described of irregular- 

 ities and imperfections in the development of the ovules and embryosacs of 

 sterile hybrids. c. j. c. 



