THE CONTINUITY OF LIFE 



" parent," and to the resultant organisms, whether two or 

 one, as the " offspring," yet it is here plain that we do not 

 have to do with either parent or children in the usual sense. 

 The " parent," as such, ceases to exist the moment it becomes 

 divided ; yet no death has ensued, for there is no dead body. 

 The vital activity of protoplasm has been perpetuated, without 

 an interruption, from the undivided mass to- each piece result- 

 ing from the fission, or in other words, the life is continuous. 

 In a restricted sense, then, a protozoan is immortal : its 



FIG. 2. Multiple fission as shown by the parasite of malaria, H<zma- 

 moeba malaria. [After Ross and FIELDING-OULD.] 



The enclosing outline represents a human blood corpuscle, within which the 

 transformation takes place. 



(a) Young amoeboid stage formed from a sporozoid. (b) Older amoeboid stage, 

 showing growth, (c) Beginning of multiple fission, .(d) Division of the mass 

 into eight sporozoids. At this stage the sporozoids become liberated through the 

 distintegration of the remains of the corpuscle, arid invade the plasma. From this 

 they enter new corpuscles, and assume the amoeboid form as at a, thus completing 

 the cycle. 



vital activities have been continuous, without interruption from 

 the beginning of life upon the planet. It is not meant, of 

 course, that a protozoan is indestructible, for countless num- 

 bers of them are continually succumbing to mechanical or 

 chemical injury; but each accident of this sort extinguishes a 

 life which has existed without cessation from the first life of 

 all. The actual material particles are constantly changing, 

 even while a protozoan is retaining its identity as an indi- 

 vidual, yet that which is continuous from moment to moment 

 in such an individual, is equally so during and after each 

 fission, and is perpetuated without interruption, in each piece, 

 so long as it does not meet with conditions which destroy it. 

 Aside from the phenomena of reproduction by fission, there 

 is another procedure which has been observed in many forms 



