148 RESEARCHES ON FUNGI 



about 8 cc. of cell-sap ; ^ and I gave the sap to my colleague Dr. H. P. 

 Armes, who very kindly undertook the task of analysing it chemically 

 in so far as that was possible with the limited amount supplied. 



Dr. Amies' analysis of the cell-sap of Piloholus longipes yielded 

 the following results : 



Total solids (dried at 150° C.) . . .1-84 grams in 100 cc. 



Inorganic matter after ignition . . 1-14 grams per 100 cc. 



The cell-sap contains : potassium, sodium, chloride, sulphate, phosphate, 

 and oxalate. 



100 cc. contains 0-26 grams ^ phosphate ion (PO4). 



100 cc. contains • 14 grams ^ oxalate ion (CgO^). 



There are indications of a carbohydrate, as shown by the Molisch 

 test. This carbohydrate is not a reducing sugar. Seliwanoff's 

 test is not given, so that sucrose is not present. Boiling with 

 dilute hydrochloric acid gives a solution which reduces Fehling's 

 solution. This might indicate a non-reducing sugar ( ? trehalose) . 



From this analysis we may conclude that the osmotic (turgor) 

 pressure of the cell-sap of Piloholus longipes is largely due to phos- 

 phate and oxalate ions, but is also due in part to potassium, sodium, 

 chloride, and sulphate ions, and in part to some as yet unrecognised 

 carbohydrate, possibly a non-reducing sugar such as trehalose.* 



The Landing of the Pilobolus Projectile and the Attachment of 

 the Sporangium to Herbage.— A sporangium, immediately after 

 being squirted of! the top of its sporangiophore, is in reality a concavo- 

 convex body which in side view (Fig. 74) has the appearance of a 

 plano-convex disc. As may be seen by reference to Fig. 30, C 

 (p. 73), it is bounded : (1) on its rounded upper and lateral sides by 

 the convex cap-like portion of the sporangium-wall, which is in- 

 tensely black except near its free margin where it is paler ; and 

 (2) on its under side, in part by the annular mass of transparent jelly 

 which on swelling split the sporangium-wall into two parts and thus 

 forced its way to the exterior of the sporangium, and in part by the 

 obtusely conical wall of the columella. To the lower margin of the 



1 The harvesting process is a tedious one ; only about 1 cc. of sap was collected 

 per hour. 



2 and ^ These amounts can be regarded as approximate only. 



* When this Section was written Lepeschkin's analysis of the cell-sap of 

 P. longipes, recorded in Chapter I, p. 25, was unknown to me. 



