INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 669 



division of apical cells lose this position, and are not correctly 

 regarded as apical cells, even if still situated near the centre. The 

 number of ajiical cells may indeed be more than one, but as can 

 be proved on mechauico-gcomctrical grounds, not so large as Kussow 

 claims for the roots of Marattiacea). This writer states that he 

 has, on a longitudinal section, observed as many as from seven to ten 

 apical cells ; Schweudener never foimd more than two in Marattia, 

 lying right and left of the median line. The complementtxry trans- 

 verse section shows altogether four apical cells. Eussow appears not 

 to have observed the true apex of the root, but a section of the root- 

 cap. The four apical cells do not touch at one point, but two of 

 them form an edge. 



Foliage shoots of Juniperus communis, seedlings of Pinus inops, 

 P. Laricio, P. sijliestris, and Abies alba, also show four apical cells, 

 two opposite ones forming again an edge. 



B. CRYPTOGAMIA. 



Cryptogamia Vascularia. 



Structure of the Fructification of Pilularia.* — According to 

 recent researches of Jm-anyi, the fructification of Pilularia globulifera 

 is a leaf-segment of peculiar form. At the time of its formation, in 

 addition to the simple sterile foliage-leaves, other bifid leaves are 

 formed, the anterior segment of each of which becomes a sporangium, 

 the posterior segment developing in the ordinary manner of foliage- 

 leaves, appearing at an earlier stage as a lateral lobe of the fertile 

 segment. The chief ground for this opinion is that the tissue of the 

 pedicel of the fructification always passes over at once into that of the 

 leaf situated behind it. 



The first ai>ix;arancc of the entire yovmg fructification is that of 

 small cylindrical masses of tissue, which subsequently assume au 

 obtuse fusiform shape, the thin-wallcd cells being filled with strongly 

 refractive protoplasm. In the centre of this tissue the procumbial 

 bundle can soon be detected, out of which the vascular buudle oi the 

 fructification is developed. At first tliis mass of tissue grows in 

 leugth nearly uniformly ; but subsequently the lower side grows 

 more rajjidly, in conseciuencc of which tlie apex of the structure is 

 elevated, and appears concave on the side wliich faces the sterile leaf. 

 With this curvature it assumes a club-like form, and forms the 

 pedicel of the now developing sporocai'p. On this are formed subse- 

 quently four sickle-shajjcd leaf-segments, from which the principal 

 part of the fructification is developed, and which form its valves. 

 They arc placed in opposite pairs, in such a way that their concave 

 side faces the centre, the convex side lying on the outside. At an early 

 period the apices of the separate leaf-segments can be distinguished, 

 and soon afterwards the cavities (lacuna) sorales) in which the 

 sporangia are formed. The margins of the two growing loaves finally 

 coalesce, while their free apices still continue their growth. After the 

 coalescence of tbe segments the young fructification is pear-shaped. 



♦ 'SIJ. UiiRar. Aka.i. d. W'iau.,' 18711, No. :>. i>. Ill (Hiiiigiiriun). Set- ' |{..(. 

 CVutiall)!.,' i. (18S0) p. 207. 



