556 SUMMARY OF CURRENT RESEARCHES RELATING TO 



as a food-material, especially in view of the fact that useless substances 

 such as resin, alkaloids, etc. are far in excess of sugar, starch, albumen, 

 etc. There is no direct evidence as to the true function of the lactic 

 fluid, although in one case at least, it appears to have the power of 

 closing up wounds, but the frequency of poisonous and unpleasant sub- 

 stances, together with the distribution of the vessels in flowers and 

 fruits, induce the author to agree with Kniep in believing that the 

 primary function rests not upon physiological but upon ecological 

 grounds. 



Anatomy of Mesozoic Conifers.*— R. Holden publishes a second 

 paper dealing with the cretaceous lignites of New Jersey. The author 

 has studied the anatomic structure of Araucarioxylon, Brachyoxylon, and 

 Cupressinoxylon with special reference to the phylogeny of the Conif erales, 

 and her chief results are as follows : an Araucarioxylon horn, the Raritan 

 cretaceous beds has bars of Sanio near the pith of the stem, resembling 

 those of the cone-axis of living Araucarinea3. The Gupressinoxyla lack 

 cellulose bars of Sanio and may therefore be regarded as a new genus— 

 Paracupressinoxijlon. Three typical Pityoxyla but not one typical 

 Araucarioxylon were found among these lignites, a fact which seems 

 to indicate that living Abietineae resemble their ancestors in all respects, 

 while the Araucarineee have become less like those of past times. k\\ 

 the Araucarinege have exactly the same wood-structure as the Abietineaa 

 down to the smallest and most unimportant details ; the anatomy of 

 the strobilus exhibits a reduction of the female cone precisely similar to 

 that of various cupressineous and taxodineous genera, and one Mesozoic 

 Araucarian (Voltzia) had a double cone-scale resembling that of Crypto- 

 meria, Thus it would appear that Conifers, as a whole, are derived from 

 the same ancestral stock, and that the Abietineae are more like that 

 stock than the Araucarinere. 



Morphology of the Leguminosse.f— J. N. Martin has made a com- 

 parative investigation of the development of the embryo-sac, embryo, 

 and endosperm of Trifolium pratense, T. hybridum, T. repms, Medicago 

 sativa, and Vicia americana. All five species resemble one another in 

 the following features: (1) the ovules are campylotropus ; (2) two 

 integuments are present, the outer of which develops first ; (3) the 

 archesporium is multicellular ; (4) there is one parietal cell which 

 divides to form more or less parietal tissue ; (5) the megaspores are 

 produced in a row of four ; (6) the nucellar tissue rapidly breaks down, 

 thus bringing the embryo-sac into contact with the inner integument ; 

 (7) the antipodal cells are transitory. They differ in the following- 

 respects : (1) in T. pratense there are always two ovules, but more m 

 the other species ; (2) in T. repens the third megaspore is sometimes 

 functional ; (3) in Trifolium the antipodal end of the nucellus breaks 

 down to form a tubular sac ; (4) in Trifolium the embryo-sac is always 

 vacuolate, but in Vicia and Medicayo it is filled with cytoplasm ; (5) the 

 place of meeting of the polar nuclei and their distance from the egg- 



* Bot. Gaz., lviii. (1914) pp. 168-77 (4 pis.). 

 t Bot. Gaz., : .lviii. (1914) pp. 154-67 (4 pis.). 



