[JANUARY 



68 BOTANICAL GAZETTE 



■ 



Ophioglossaceae.— C-\MPBELL^^ has published an account of his studies of 

 East Indian species of Ophioglossum. He collected O. moluccaniim, O. inter- 

 medium^ and O. pendulum, securing both gametophytes and sporophytes in con- 

 siderable number. The spores of O. moluccamwt germinated freely, but owing to 

 a failure to become associated with the mycorhizal fungus the prothallia died 

 after reaching the four-celled stage. ProthalUa of O. pendulum made the myco- 

 rhizal connection and reached the thirteen -celled stage. They did not develop 

 any chlorophyll on exposure to light, although a few chloroplasts developed in the 

 prothalHa of O. nioluccanum. The adult gametophyte in all the species studied 

 is subterranean, without chlorophyD, and radiate in structure. Campbell's 

 account agrees closely in this regard with the accounts of Mettenius, Laxg, and 

 Bruchmann. The account of the development of the antheridium is also essen- 

 tially the same as that given by these authors. The statement is made that in die 

 mitosis immediately preceding the formation of sperms the number of chromo- 

 somes is much larger than in the earlier divisions. Most cytologists wiU regret that 

 this interesting situation was not investigated somewhat further. The development 

 of the sperm agrees closely with that of Equisetum. The archegonia resemble 

 those of the Marattiaceae. There is either a binucleate neck canal ceil or two 

 neck canal cells. The ventral canal cell is difficult to demonstrate, but was 

 shown to be present in O. pendulum and probably in the others. The primary 

 wall in the embr}-o is transverse in most cases, but varies considerably, particularly 

 m O. pendulum. The entire hypobasal half goes to the formation of the foot. 

 There are three types of embrj-o: (i) that of O. moluccanum, in which only root 

 and leaf are developed, the plant being annual and no stem being produced; (2) 

 that of O. vidgatum, in which root and stem are first produced, and much later a 

 leaf; and (3) that of O. pendulum^ m which root only is produced, stem and leaf 

 arising later by means of an endo^nously developed bud from the primar>^ root 

 at some distance from the gametophyte; the vascular bundles of leaf and stem arise 

 separately from die bundle of the root and remain separate. 



In O. moluccanum the primary root is monarch and the bundle of the leaf is 

 collateral, and Campbell says that it is merely a question of terms whether one 

 calls the root monarch or coHateral. The primary root of O. pendulum is diarch, 

 as are also the later roots. The O. moluccanum type of embn^o is probablv the 

 most primitive and is most nearly related to the embr}'os of "Marattiaceae and 

 Equaetineae, especially to the former. The author^s weU-known claim that 

 Ophiogiossum is a primitive t>'pe of pteridoph}tes is emphasized by his somewhat 

 detailed explanation as to how die O. moluccanum t>^pe might have arisen from 

 an Anthoceros-like ancestry.~L. Laxck BimiNGAMi: 



Stw^lity in hybrids. 



;chle 



further investigation on the causes of sterility in hybrids. lie has studied FotentiHa 



32 



Campb 



IL 6:138-194. ph,^ig. igoy, 



=^3 TiscHLER, G., Weitere Untersuchungea uber Steri 

 pSanzen. Ber. Deutsch. Bot. Gesells. 25:376-383. 1907 



Ann. Tard 



