Hkuon-Ali.I'.n and Kahi.ani) — Shuhj (ij Verncuilinapoli/titropha. 161 



present we know piacLically nolliiiig cm wliicli a truly seienlific system can 

 be based. Indeed, as J. J. ]>ister has jnstly observed, "until these early 

 stages have received fuller attention, and we have arrived at a conclusion as 

 to the relation of tlie early to the later stages t>f the multiform tests, eflbrts 

 at forming a ' natuial classitieation ' appear to be premature. "-- 



(iii) The tliird form of variation, already recognized, is ^■aliation oi 

 e.xternal form, the intermediate or "passage" forms, " o^:x," to which we 

 have already referred. The extreme aspect of this modification is to be found 

 iu the monstrosities to which we have also referred, and shall refer again 

 later. Some of tliese variations are inexplicable, being combinations of 

 widely difl'erentiated genera, such as the specimen half Globigerina and half 

 Nodosaria, figured by Heron-Allen iu his paper on Bionomics in 1915." 



Since that time we have come across other equally incomprehensible 

 combinations of widely separated (so-called) genera, notably a Textularian, 

 which, after completing its biserial shell, became in the later chambers a 

 perfect Glohigcrina dntertrci, d'Orbigny, found in the " Terra Nova" dredgings 

 (Stn. 96, New Zealand Benthos., Stn. 4) (tig. 3). A Miliolina terminating in 

 a series of chambers set at an angle to the test which were cornuspirine with 

 a tendency to Opthalmiilium, gives us a further instance (fig. 4), in this case 

 the later growth taking the form of more nearlv related genera. 



It is a question whether the fistulose Polyniorphinae should be regarded 

 as "monsters." We are inclined to the view that all free specimens of 

 fistulose Polyniorphinae have originally lived in the sessile condition, aud 

 that the fistulose out-growths represent no more than a protective covering 

 secreted by the animal to protect the streaming protoplasm emerging from 

 the orifice. In other words, that the fistulm are homologous with the sandy 

 tubes radiating from Valvulina and other forms which are normally sessile. 

 Alcock has suggested"* that this listulose cimdition results from senility and 

 weakness, the protoplasmic body of the organism being no longer able to 

 control its own development and the fashion of its calcai'eous investment. 

 But it seems to us that if Alcock's theory were correct, fistulosity would be 

 found at least in all species of Polymorphina, and probably in other genera 

 as well, whereas this form of variation is practically confined to a few species 

 only. 



-- Loc. cit. (note 6), p. 140. 



-' E. Heron- .\lleii : "Contributions to the Study of the Bionomics and Reproductive 

 Processes of tlie Foniminifera." Pliil. Trans. Roy. Soc. Ser.B, vol. ccvi, 1915, p. '2o\, 

 PI. xvi, fig. 34. 



-^T. Alcock: " Proc. Lit. Pliil. Soc. Mancliester," 3rd Ser., vol. iii, 1806-7, aud 

 vol. xxii, 1883, p. fi8. 



