INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY^ ETC. 475 



substances. "While tlie outer wall of the embryo is strongly cuti- 

 cularized, that of the suspcnsor consists of pui'e cellulose. 



In Herminium MonorcMs the cells of the suspensor put out 

 branched filiform ajipendages which creep over the placentae. In 

 Goodyera repens and Phajus WallicMi the suspensor is unicellular, 

 and attains a great length, but does not project beyond the exostome. 

 In these and similar cases the food-material appears to reach the 

 suspensor through the funiculus. 



In some species of Phalinnojms the suspensor consists of a bundle 

 of slender unicellular filaments which are fixed by tbeir middle to 

 the upper part of the embryo, the free end hanging down and project- 

 ing beyond the endostome, rarely beyond the exostome also. 



In Stanliopea peculiar thick filaments hang above the embryo, tho 

 history of whose development has not yet been sufficiently investigated 

 to determine whether they constitute a true susjjonsor. 



The axithor does not adopt the prevalent view that the embryo of 

 the Orchidacese is entirely destitute of a cotyledon. He accepts, on 

 the other hand, that of Pfitzer, that although of exceedingly simple 

 structure, a cotyledon is to be detected in the apical part of the 

 embryo. 



Formation of Starch-grains and Composition of the Cell-wall.* 

 — Professor Frommann states that he has detected in growing cells a 

 thread-like reticulated structure, both in the protoplasm and nuclei 

 and in the chlorophyll-bodies, and that these not merely serve to 

 connect the nuclei and chlorophyll-bodies with one another, but that 

 they pass from one cell to the next through minute crevices in the 

 cell-wall. This passage of the threads into the cell-wall can be made 

 out through the whole extent of the primordial utricle, and they pass 

 even into the cuticle. The author suggests that these are connected 

 with the continual fresh formation of cellulose. The starch-grains 

 are formed in the same way, within the chlorophyll-bodies, from a 

 similar network of threads of protoplasm, which are hero and there 

 swollen into knots. 



The observations were made chiefly on the epidermal and paren- 

 chymatous cells of Dracaina and of lihododeudron ponticum. A 

 magnifying power of 900 is required to make out tho structure in 

 question. 



Transfusion Tissue, j — This term was first employed by Von Mohl 

 to designate a tissue widely distributed in tlie Couiferrc, and peculiar 

 to that order. Its special scat is in the leaves, occurring always in 

 connection with the vascular l)undles. To this rule there is no 

 exception in tliose species in wliich the leaves are free; in those in which 

 they are partially adherent to the stem there is only one, Cuprcssus 

 8enij)er lire Its, where the transfusion cells are situated at the base of 

 the leaf, and separated from tho vascular bundle by a layer of 

 parenchyma containing chlorojdiyll. The position of tho tissue in 

 relation to tho vascular bundle is very various, tho most common, us 



• 'SH. .Jeimi.-ohc Cun. Med. u. Nuturwies.,' ISTU, p. 111. 

 t 'Fluni,' Ixiii. (1880) p. '2. 



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