442 Journal of Applied Microscopy. 



CURRENT BOTANICAL LITERATURE. 



Charles J. Chamberlain. 



Books for review and separates of papers on botanical subjects should be sent to 



Charles J. Chamberlain, University of Chicago, 



Chicago, 111. 



REVIEWS. 



Schrenk, Hertnana von. A Sclerotioid Disease A large number of root tubercles at- 

 of Beech Roots. Contributions from the ^ , i ^ ^, <:i ^ c ^ r 



Shaw School of Botany, No. 13. Report tached to the fibrous roots of a clump of 



Mo. Bot. Garden. 10: 61-70, pi. 55-56. beech trees led to these investigations. 

 ^^' It has long been known that roots of 



the beech, when growing in humus soil, are surrounded at their tips by a mantle 

 of fungus threads known as mycorhiza. Such roots branch freely, are usually 

 coralloid in form, and grayish white in color, but are not contorted or hypertro- 

 phied. This mycorhiza form of root was found on all the beeches of the locality, 

 but the tubercles described in this paper were confined to certain clumps of trees. 

 The tubercles are grayish white bodies, varying in size from almost invisible 

 specks to masses as large as small peas. The tubercles consist of a number of 

 contorted, interwoven roots, covered by a fungus sheath in which two layers can 

 be readily distinguished. The outer, thicker layer is composed of large septate 

 hyphae, which branch freely and anastomose, thus forming a dense sheath which 

 can be pulled off. The inner layer is composed of very fine, interwoven hyphae, 

 which also surround the individual rootlets. The epidermal layer of the root 

 has a peculiar structure, the cells being elongated so as to resemble a palisade. 

 The hyphae are closely appressed to these epidermal cells, but unlike the hyphae in 

 mycorhiza, they do not enter. The root tip is simplified, the cap consisting of 

 only two layers of cells. The meristem cells are larger than those in roots of 

 the mycorhiza. The fact that many small sclerotia were found associated with the 

 tubercles suggests that the hyphae may belong to some Hymenomycete. The 

 fungus of the outer layer of the sheath is probably distinct from that forming 

 mycorhiza. The occurrence of several different forms of mycelium, some closely 

 associated with roots and claiming symbiotic relationship, and others more dis- 

 tinct from the root, as in the case of the root tubercles, suggests that the relation 

 of root fungi to trees is still an unsolved problem. c. j. c. 



Campbell, D. H. Notes on the Structure of the The most Striking feature in the embryo- 

 Embryo-sac in Sparganium and Lysichiton. g^^^g q£ ^Q^h these forms is the remark- 

 Bot. Gaz. 27: 153-164, pi. 27, 1899. i, , , . r ., ^- i 1 u 



able development of the antipodal cells. 



In Sparganium the number sometimes reaches one hundred and fifty, thus 



exceeding the extensive antipodal development of grasses. In Lysichiton the 



number of antipodals is not so large, probably never exceeding ten, but they 



increase considerably in size. In both forms this vigorous development begins 



after fertilization. While the antipodals probably represent prothallial tissue, 



they must not be regarded as mere vestiges of a prothallium, since their great 



development and relation to nutrition shows that they are also of physiological 



importance. The behavior of the antipodals, and also the morphology of the embryo 



