75 ° 
Dig by.—The Somatic , Premeiotic, and 
In Trollius europaeus he has shown the alveolization of the chromosomes in 
the telophase of the last archesporial division, but unfortunately there is 
a rest between the telophase and the early heterotype prophase, so that it 
is impossible to trace the relationship between the portions of alveolized 
chromosomes of the telophase and the * Gamosomen ’ of the prophase. 
Gregoire ( 11 ) (1910) thus defines the difference between the somatic and 
heterotype prophase: ‘ Tandis que, dans une cinese somatique, on voit le 
reseau quiescent se decomposer typiquement en des bandes alveolaires ou 
en des tractus qui, par un mouvement de concentration, se transforment en 
chromosomes homogenes definitifs, ici (stades prespirematiques) au contraire, 
il se forme aux depens du reseau . . . . un ensemble de filaments minces 
generalement assez long.’ Further, that in the pollen mother-cells of 
Allium ‘ le passage du stade reseau au stade leptotene se fait par l’intermd- 
diaire de bandes chromosomiques alveolisees analogues a celles qui marquent 
la premiere origine des chromosomes somatiques, et que c’est de la trans¬ 
formation de ces bandes que resultent les filaments minces par un processus 
analogue a celui que l’on retrouve dans les cineses somatiques. ... II n’y a 
done pas de doute, a notre avis, que chaque filament mince ne soit l’homo- 
logue d’un chromosome.’ From these quotations it is clear that Gregoire, 
in the somatic prophases, considers each ‘ filament mince ’ to be the longi¬ 
tudinal half of a somatic chromosome, whilst in the heterotype prophases he 
considers each 4 filament mince ’ to be a whole somatic chromosome. Gregoire 
perhaps makes insufficient allowance for the concentration of each univalent 
chromosome in the heterotype prophase which plays such a prominent part 
in the formation of the chromosomes in the somatic divisions. 1 
(2) One of the chief upholders of the opposed view that the parallelism 
in the heterotype prophases may possibly be the longitudinally split halves 
of the same chromosome is Hacker ( 12 ). He says: ‘ Ob nun freilich diese 
paarige Anordnung der prasynaptischen Chromosomenanlagen tatsachlicher 
auf eine Aneinanderlegung ursprunglich selbststandiger Elemente zuriickzu- 
fiihren ist, das scheint mir angesichts der grossen Schwierigkeiten, welche 
die folgende Synapsis-Phase der Analyse darbietet, noch nicht mit 
Sicherheit entschieden zu sein. Ich mochte vielmehr auf alle Falle die 
Moglichkeit offen lassen, dass z. B. in den von Overton gegebenen Bildern, 
nicht eine Chromosomenpaarung im Sinne Strasburger’s, sondern die 
Anlage eines friihzeitig gespaltenen Spirems im urspriinglichen, von Flem¬ 
ming ( 5 ) angenommenen Sinne vorliegt.’ 
Meves ( 19 , 20 ) (1907,1908) finds that the parallel threads of the somatic 
and heterotype prophases are so closely similar that they must bear the 
same interpretation. Moreover, he considers that the threads are too thick 
1 Since this communication has gone to the printers another paper on prophases has been 
published, entitled : Kerndeeling en Synapsis bij Spinacia oleracea, L., by Theodor J. Stomps, 
Amsterdam, 1910, pp. 1-162. 
