830 SUMMARY OF CURRENT RESEARCHES RELATING TO 



becomes tho suspensor, the other is tlio mother cell of the embryo ; 

 tho latter develops ultimately into a multicellular mass arranged in 

 two tiers ; tho lower tier forms only tho massive " foot," while from 

 tho upper (i. e. that further from tho neck of the archegonium) arc 

 derived the stem and singlo cotyledon, and ultimately also the first 

 root. Tho first root of L. Phlegmaria is at first covered by an 

 envelope, a single layer of cells in thickness, which cannot rightly bo 

 regarded as the outermost layer of the root-cap; accordingly, wo 

 havo tho barest possible cxamplo of endogenous formation, only a 

 step removed from the exogenous. As far as it is possible to judgo 

 at present, wo find in the sexual generation of the Lycopods, more 

 clearly than elsowhcre, transitional terms between tho great series 

 of the Muscincrc and that of tho Vascular Cryptogams. 



A peculiar case of symbiosis occurs in the prothalli of L. Phleg- 

 maria. Endophytic Fungi havo already been described in prothalli 

 of other species,* and here Dr. Treub finds the tissues constantly 

 infested by a fungus, apparently ono of the Peronosporeso. Its thin 

 filaments inhabit tho interior of tho cells themselves, but without 

 killing them, the nuclei of tho cells remaining normal, while the 

 growth of the prothallus does not appear to be visibly hindered by 

 its presence. It would appear that we have here a case of " com- 

 mensal " symbiosis, in the strictly literal sense. 



Rabenhorst's Cryptogamic Flora of Germany. — Parts 4-7 of 

 the third vol. of this work continue the account of the ferns through 

 the genera Aspidium, Ceterach, Phcgopteris (P. polypodioides, Dryo- 

 pteris, and Pobcrtiana), and a part of Aspidium. Tho descriptions arc 

 carried out by Dr. Lucrssen in great detail, many of the varieties 

 being described, as well as the species. The woodcuts are excellent. 



Muscineae. 



Microspores of Sphagnum.f — Herr C. Warnstoff confirms tho 

 old observation of Schimper of the occurrence of two kinds of spore 

 in tho Sphagnacese. The microspores he finds to havo a diameter of 

 0' 012-0 -018 mm., in contrast to that of the ordinary spores, from 

 0*030 to 0*033. In Sphagnum acutifolium and acutiforme he found 

 them in special microsporangia, either on separate plants from the 

 macrosporangia or intermixed with them ; in S. Girgensohnii in the 

 same sporangium as the macrospores, and resembling them in every 

 respect except size. He was unable to ascertain their function, or 

 whether they are capable of germination. 



Physiotium.ij: — Herr J. B. Jack gives a complete monograph of 

 this genus of Jungernaannieaa, comprising ten species, all tropical. 

 Besides the inflated or vesicular character of the lower lobes of tlio 

 leaves, the genus is characterized by the presence of peculiar tubular 

 organs, either scattered over the ordinary branches or at the apex of 

 special branches. Their function is unknown, but they may possibly 

 be barren perianths. 



* Cf. this Journal, v. (1S85) p. 839. 



t Hedwigia, xxv. (1S8G) pp. 89-92. $ Ibid , pp. 49 87 (10 pis). 



