243 
antheridium and antherozoids. Absence of the ventral canal-cell 
in the archegonium. Succession of the divisions of the embryo — 
and the establishment of the apical cells of its different members. 
Development of the different tissues of the embryo. Development 
of the leaf from the apical cell, and the relation of the different 
tissues of the leaf to the segments of the apical cell. Method of 
formation of the pinne. Development of the stem from the 
apical cell. Development of the sporangium.” 
“The sporangia in this fern are borne in great numbers in 
the back of the fertile fronds, and as these remain standing 
through the winter after the sterile fronds have decayed, spores 
can be obtained at all seasons of the year. These retain their 
vitality for several months after being gathered, so that when 
the plants are common, abundance of material is constantly on 
hand. This fact, together with the ease with which the spores 
can be germinated, makes the plant a specially valuable one for 
study.” 
Philadelphus microphyllus, Gray. (Gard. Chron. ii., 1887, p. 
156; illustrated.) 
Plante Nove Hispanie.—Martinius Sessé et Ioseph Mariannus 
Mocifio. (La Naturaleza, II Ser., i., pp. 16.) 
In this valuable Mexican periodical we find a list of plants 
dating from the time of Chas. IV., which has been lying perdido 
in Spain and is now printed for the first time. The classification 
is the Linnzan, and the descriptions are in Latin. The title page 
announces plates from the original drawings, but there are none 
in this number. 
Plants of the Island of Rhode Island— Native, U1.—W. C. Rives, 
Jr. and W. W. Bailey. (Proc. Newport Nat. Hist. Soc., 1886- 
87, Py: 32-35.) x 
This completes the list begun in a former number. 
Potamogeton Mexicanus, Bennett. (Journ. Bot., xxv., p. 289.) 
This new Potamogeton belongs to the same group as P. flut- 
tans, with a fruit resembling P. ¢ricarinatus but much larger. 
P. Claytonti, Tuck. (Silliman’s Journ., 1843,) is antedated by 
P. Pennsylvanicus, Cham. (Linnza, 1827,) as specimens “in 
Willdenow’s herbarium at Berlin, are named by Chamisso and 
_ intialled by ‘Prof. Tuckerman as his Claytonii."’ 
