72 BIOLOGY OF THE PROTOZOA 



generative component (as in Heliozoa with central granule, or 

 Trypanosomes with "kinetonucleus"). Polyenergid types, finally, 

 involve nuclei containing an aggregate of monoenergid nuclei. Since 

 a monoenergid has but one kind of division Hartmann assumes 

 that this division may take place while in the aggregated condition; 

 or that the monoenergids are freed by rupture of the membrane 

 after which they may divide as monoenergids in the cytoplasm. 

 In all cases the monoenergids become the nuclei of gametes (as in 

 Radiolaria, Foraminifera and gregarines). The conception is inter- 

 esting, but apart from adding other somewhat unenlightening terms 

 meroenergid and polyenergid it leaves us practically where we were 

 before on the chromidia problem, and separates, without sufficient 

 justification, the chromidial net type from the gamete nuclei type. 

 In all probability the two types are not widely different. The 

 monoenergids which come from a polyenergid nucleus represent 

 chromatin which is formed in the nucleus (see p. 87) ; the gamete 

 nuclei which arise from the chromidial net represent chromatin 

 which is manufactured by a cytoplasmic substance of the same 

 nature as the karyolymph and a substance which, possibly, may 

 be derived from the nucleus. 



2. Volutin Grains.— These are widely distributed in Protozoa with 

 the exception of the Infusoria, and are not difficult to distinguish 

 from chromidiosomes. They are usually spherical in form but may 

 be angular and irregular and stain intensely with the basic dyes, 

 retaining the stain even after the chromatin granules are completely 

 extracted. They were discovered by a pupil of A. Meyer in the 

 cells of Spirillum volutans from which the peculiar name is derived, 

 and, according to Guilliermond, they are identical with the "meta- 

 chromatic bodies" of Babes, and with the "red granules" discovered 

 by Biitschli. They take a yellow stain with iodine and a blue stain 

 with methylene blue and 1 per cent solution of sulphuric acid, 

 while their reaction to the usual chromatin stains makes them 

 difficult to distinguish from chromidia. They do not give a reaction 

 with the Feulgen method as usually employed, but Reichenow (1928) 

 found that if the preliminary acid hydrolysis is omitted a typical 

 Feulgen reaction follows upon treatment with the fuchsin-sulphuric 

 acid component alone. He infers from this that volutin substances 

 give a typical Feulgen reaction, which is much more rapid than 

 that of nuclear chromatin, and concludes that volutin consists of 

 free nucleic acid. The same conclusion was reached by Schumacher 

 (1926) on the basis of volutin reactions to his methylene blue phos- 

 phin method. Meyer himself regarded them as composed largely 

 of nucleic acid, a conclusion supported by the experiments of 

 Reichenow (1909) on Hematococcus in which it was shown that 

 volutin grains disappear in a medium free from phosphorus and 

 that, during the phases of active chromatin increase in the nucleus, 



