6 THE SAPROLEGXIACEAE 



the spores frequently sprouting by the A planes method (see below). 

 Variations in the discharge and beha\'ior of the spores are recorded in 

 the following cases (many others are recorded under the species in this 

 book) : 



Achlya aplanes JMaurizio ('94). The behavior of the spores as described 

 in this case is very peculiar. There is no swimming stage, the spores 

 on emerging sprouting into tubes. Frequently they do not emerge 

 at all, but remain in the sporangium and sprout there. (That these 

 statements hold true regularly under normal conditions must, I 

 think, remain doubtful until the plant is studied by some one else). 



Achlya caroliniana Coker ('10). The spores may be retained and sprout 

 as in Aplanes, or under certain circumstances may emerge in a motile 

 condition. They may also emerge from several mouths. Later 

 observation by me shows that under certain conditions as on Qgg 

 yolk in i per cent KN2PO4 the spores may not stick to the sporan- 

 gium mouth, but fall to the bottom in open order. This is true 

 also of A. flagellata (see our treatment). 



Achlya deBaryana Humphrey (Achlya polyandra deBary): Coker ('12). 

 Figs. 7 and 8, of plate 78, show reduced sporangia with spores in 

 a single row, the spores emerging exactly as in Dictyuchiis. They 

 also frequently sprout as in Aplanes. 



Achlya glomerata Coker ( '12a). In fig. 7, plate 79, is shown a sporangium 

 with the spores sprouting as in Aplanes. 



Achlya polyandra Hildebrand: Ward ('83). In plate 22, fig. 8, is shown 

 a sporangium with the spores emerging just as in Dictyuchns. The 

 retention of the spores in this case he was able to bring about by 

 poor aeration, i.e., placing the culture in an air-tight chamber. 



Achlya prolifera (Xees) deBary ('52). In plate 7, fig. 28, is shown the 

 sprouting of the spores at the mouth of the sporangium, the second 

 swimming stage omitted. In all the species of Achlya that I have 

 studied the second swimming stage may be easily suppressed. 



Achlya racemosa Hildebrand: Pringsheim ('73). In plate 22, figs, i, 2, 

 and 3, are shown sporangia emptying exactly as in Dictyiichus. 

 Under the name oi Achlya lignicola, which I am treating as a variety 

 of A. racemosa, Hildebrand figures a sporangium with many of the 

 spores remaining undischarged ('67, pi. 16, fig. 2). In both A. 

 racemosa and A. colorata the emptying spores hang together im- 

 perfectly and often separate into se\-eral groups. 



Achlya dubia Coker (see p. 135). In this species the sporangia discharge 

 their spores in part as in Achlya and in part as in Thraiistotheca; 

 also not rarely as in Dictyiichns. 



