igi2] CURRENT LITERATURE 553 



Morphology of Uvularia. — Miss Alden 27 has investigated the life history 

 of Uvularia sessilifolia, chiefly as to the sequence of events, presumably in the 

 region of New York City. The archesporium of the microsporangium (3-6 

 cells) becomes differentiated the first of August, at which time also the division 

 into parietal and sporogenous series occurs. Mature microspore mother cells 

 were found in the middle of September, and the tetrad divisions occurred in 

 October, so that the winter is passed with the microspores fully formed. In 

 the latter part of the following April the division of the microspore nucleus 

 into generative and tube nuclei occurs, and probably the former divides after 

 the shedding of pollen. The archesporium of the megasporangium is differen- 

 tiated early in March (seven months later than the microsporangiate arche- 

 sporium), and consists of a single hypodermal cell which does not cut off a 

 parietal cell. The reduction division occurs the last week of April. — J. M. C. 



Spermogonium and fertilization in Collema. — Miss Bachmann 28 has 

 investigated Collema pulposum as to the nature of the spermatia and its bear- 

 ing on the question of functional sexuality among the Ascomycetes. The 

 spermatia of this species are not born in spermogonia, but few in number upon a 

 hypha below the surface of the thallus, being completely imbedded and never 

 set free. The carpogonia resemble those of other lichens in general structure, 

 but the long end cell of the trichogyne does not grow toward the surface of the 

 thallus, but more or less horizontally within the thallus toward the region of 

 the spermatia. The attraction of the spermatia for the trichogynes is shown 

 by the convergence of the latter about a group of spermatia. The spermatium 

 fuses with the trichogyne to which it has become attached, and the subsequent 

 changes are those that have been described. It seems evident that in this 

 case the spermatia and trichogyne are functional. — J. M. C. 



Seedling anatomy of Sympetalae. — Lee 29 has investigated the seedling 

 anatomy of Convolvulaceae, Polemoniaceae, Hydrophyllaceae, Boraginaceae, 

 Labiatae, Solanaceae, Scrophulariaceae, Bignoniaceae, and Acanthaceae. The 

 extent of the transition region is related in a general way to the size of the 

 seedlings, which varies greatly in different species. In the smaller seedlings 

 the transition region is short, and the rearrangements are concluded in the 

 upper part of the hypocotyl; while in the larger seedlings the transition region 

 is very extended. Cotyledonary tubes occur in members of all the families, 



a 7 Alden, Isabel, A contribution to the life history of Uvularia sessilijolia. Bull. 

 Torr. Bot. Club 39:439-446. pis. 34, 35. 1912. 



28 Bachmann - , Freda M., A new type of spermogonium and fertilization in 

 Collema. Ann. Botany 26:747-760. pU 6g. 191 2. 



29 Lee, E., Observations on the seedling anatomy of certain Sympetalae. I. 

 Tubiflorae. Ann. Botany 26:727-746. pi. 68. 1912. 



