1 82 Tratisactions of the [Sess. 



fact that the Sponge cell is capable of forming amyloid substance, and 

 depositing it in vacuoles in large quantities." It has, moreover, been 

 suggested that this amylum is in some way related to the formation 

 of winter gemmules, to which they may act as a store of food- 

 material, being " most abundant in specimens of Spongillaa which are 

 actually breaking up and dying down at the incoming of Avinter " 

 (Lankester, 'Quart. Jour. Micr. Sci.,' 1882). In connection with 

 this, the ingenious suggestion of the mechanics of sinking or floating 

 of Eadiolarians, given by Mr Geddes, is worth noting : " The starch 

 formed during the morning's exposure to sunshine would increase the 

 specific gravity of the Eadiolarian, and so sink it ; while its digestion 

 and oxidation would again lighten it," and so cause the animals to 

 float nearer and nearer to the surface of the water. 



The analytic method adopted by Dr Geza Entz (' Biol. Centralbl./ 

 20th Jan. 1882) for demonstrating the independent nature of some 

 consortial Algse is especially interesting. He has succeeded in remov- 

 ing green bodies from Infusors, and has traced their development to 

 adult algoid genera — PalmeUa, Gloeocystis, and Pleurococcus ; while he 

 has, conversely, observed the entrance of spores of these animals into 

 Infusors. About the same time. Professor Percival Wright (' JSTature,' 

 Feb. 1882) also recorded the entrance of Chlorochytrium and other 

 algoid spores into the bodies of animals, having previously (in 1877) 

 suggested a possible relationship to the Lichen-gonidial theory. 



Finally, Dr Brandt ('Mt. Zool. Stat, ^^eapel.,' vol. iv., 1883) has 

 pointed out curious changes of colour observable in the case of con- 

 sortial Algse found at difi'erent depths. Thus yellowish-green or 

 yellow forms occur in surface animals like Eadiolaria, brown forms 

 are found in animals occurring at a slight depth, while red types 

 occur in Phytozoa procured from still greater depths, such as Sponges. 



In dealing with the great family of Lichens, so abundantly distri- 

 buted over every stone and tree, we have again to face commensal 

 problems, although it is only in recent years that the complete rela- 

 tionships of the associated organisms have been fully and securely 

 established. Thirty-five years ago Tulasne sowed Lichen spores, and 

 believed that he detected gonidia forming on the fungoid hyphoB. 

 This same conception was originally held by De Bary in his ' Mor- 

 phology and Physiology of Fungi,' where he remarks that a lateral 

 branch of the hypha becomes shut off" by a wall, and requires chloro- 

 phyll, so forming a gonidium capable of subsequent subdivision ; 

 although in his ' Handbook of Physiological Botany ' (p. 2 9 1 ) his 

 views become modified. Lichens being regarded as the complete 

 fructifying states of plants hitherto called Algae, or as typical Algse 

 that become " Lichens " because of the Fungus. The original view of 

 Tulasne was also adopted by Berkeley (' Introd. Crypt. Bot.,' p. 273), 

 and folloAved by Thwaites. But the researches of Schwendener 

 ('Ueber die Algentypen der Flechtengonidien,' 1869) first demon- 



