178 O. P. Bellinger. 



(1884-5-6), Ballowitz (1881 and later, 1888 and 1890), Rabl 

 (1889), Schneider (1891 and later), Klein (1878 and 1879), Apathy 

 (1891), and, more recently, Heitzmann (1894), Schenk (1897 and 

 1900), Arnold (1898), Allen (1903), Schneider (1903 and 1905), 

 Reinke (1905), Parker (1905), Dellinger (1906), Hodge and Del- 

 linger (unpublished), etc. 



Although in recent years the results of many investigations have 

 been opposed to this theory of the structure of protoplasm, the last 

 two researches just mentioned have taken away much of the founda- 

 tion on which opposition was based, and there is little doubt that it 

 will prove nearer correct than any developed to take its place. 



Englemann's Inotagmas. 

 A modification of the fibrillar theory was brought forward by 

 Englemann in 1868 and further developed by him in 1879 and '80. 

 According to him, protoplasm is an aggregate of minute contractile 

 and ^'reizbar Formelemente." The phenomena of movement are the 

 result of the change of form of these minute elements. Englemann 

 names these contractile elements "Inotagmen." He thinks of them 

 as molecular in size, spherical in form when contracted, and thread- 

 like when at rest. The reasons for these assumptions are : First, that 

 protoplasm in however small masses takes on a spherical form when 

 contracted. Second, that when relaxed protoplasm shows often fine 

 fibrillar striations and is, in its finest division in contractile struc- 

 tures, a "langgestrecl-te FormJ^ Contraction is brought about by a 

 change of turgidity, as the element would i)robably shorten with an 

 increased turgidity and would stretch out again after giving oft' fluid. 



Strashurger's Kinoplasm and T rophoplasm. 

 Strasburger (1892 and later) and many other botanists who have 

 followed him divide protoplasm into two substances, his kinoplasm 

 and trophoplasm. Of these the kinoplasm is active, entering into the 

 formation of the fibrillae of the spindle and other active organs of the 

 cell, such as the cilia, centrospheres, centrosomes and the cell mem- 

 branes, while the trophoplasm is nutritive. The above classification 

 implies a physiological difference in the two substances. 



