774 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of the mitochondries. Investigations of the lower plants, e.g. Fungi, 

 Alira 1 . etc. were not very successful, but mitochondries were found in 

 the asci of Pustularia vesiculosa. Seeds of the higher plants were 

 especially rich in mitochondries from the commencement of germina- 

 tion, both in the endosperm and in the tissues of the embryo. They 

 varied in form, being rod-like in Rieinus, and spherical in haricot beans ; 

 they were specially abundant in barley, wheat, and maize. In barley 

 they were present in the cotyledons until the latter began to wither, and 

 in other organs of the embryo they persisted in the meristem until the 

 tissues were differentiated. In parenchymatous cells their disappearance 

 coincides with the appearance of the chloroleucites, and in the pro- 

 cam Itial strands with the differentiation of the fibro-vascular bundles. 



Structure and Development. 

 "Vegetative. 



Splitting of Rhizome and Root of Delphinium.* — M. A. Kingsley 

 has examined several specimens of Delphinium scaposum, and rinds 

 that the most apparent characteristic common to all is the manner of 

 splitting of the rhizome and root. The following are the chief points 

 of interest : — The primary root-structure is regular. The cambium 

 produces an annual ring of xylem and phloem, but both elements are 

 frequently replaced by parenchyma. There is an endodermis between 

 the outermost spongy cortex and the regular outer parenchyma. In 

 the third year an inner endodermis cuts off the primary xylem, paren- 

 chyma and necrotic pith from the rest of the tissues. The outer 

 endodermis pushes between the xylem, joins the inner endodermis, and 

 makes a continuous ring about each of the segments thus formed. The 

 tissues thus cut off become necrotic. Columns arise, surrounded by 

 active cork-forming periderm ; these have an independent existence, and 

 never exceed the number of the original bundles. 





Epidermal Characters of Frenelopsis ramosissima.f — Edward 

 Wilber Berry notes that the genus was founded by Schenck in 1869 

 upon abundant material from the Lower Cretaceous, and named from its 

 resemblance to the modern genus Frenela. The species has since been 

 recognized in Greenland, Texas, New Jersey, and France. In 1880 

 Hosius and Van der Marck described Frenelopsis Kdnif/ii, from West- 

 phalia, and in 1881 Heer described F. occidentalis, from Portugal. 

 The latter also described F. leptoclada, which is confined to the Lower 

 < 'retaceous of Portugal. In 1889 Yelenovskv described F. bohemica 

 from the Cenomanian of Bohemia, and in 1890 Fontaine described 

 /•'. ramosissima and F. parceramosa, from the Potomac group of Virginia, 

 the same author in 1893 founding a third species, F. varians, upon 

 material from the Trinity group. Newberry (1896) described a ninth 

 species, F. gracilis, an abundant Upper Cretaceous type, which has been 

 recently shown by Hollick and Jeffrey to be unrelated to Frenelopsis. 



* Bull. Torrey Bot. Club, xxxviii. (1911) pp. 307-17 ( 2 pis. and 1 fig.), 

 t Bot. Gazette, 1. (1910) pp. 305-9 (2 figs). 



