diff --git a/Plague.g1a b/Plague.g1a
index b376a84..7b2250b 100644
Binary files a/Plague.g1a and b/Plague.g1a differ
diff --git a/Plague.g3a b/Plague.g3a
index 1e2d87a..a553e2f 100644
Binary files a/Plague.g3a and b/Plague.g3a differ
diff --git a/assets/bground.png b/assets/bground.png
index a5187b2..b40d9a0 100644
Binary files a/assets/bground.png and b/assets/bground.png differ
diff --git a/src/data.c b/src/data.c
index 29a2f05..1d024a6 100644
--- a/src/data.c
+++ b/src/data.c
@@ -35,7 +35,7 @@ const struct mutation abilities_data[6] =
 const struct mutation transmissions_data[13] =
 {
     { 5,  0, 0,  5, 0, "AIR 1", "TRANSMISSION PAR L'AIR"},
-    {10, 10, 0, 15, 0, "AIR 2", "TRANSMISSION PAR L'AIR"},
+    {10,  0, 0, 15, 0, "AIR 2", "TRANSMISSION PAR L'AIR"},
     {20, 10, 0, 20, 0, "AIR 3",  "TRANSMISSION PAR L'AIR"},
     {40, 15, 0, 30, 0, "AEROSOL", "TRANSMISSION PAR L'AIR ET PAR L'EAU"},
     {10,  0, 0, 15, 0, "EAU 1", "TRANSMISSION PAR L'EAU"},
@@ -45,7 +45,7 @@ const struct mutation transmissions_data[13] =
     {20,  0, 0, 15, 0, "OISEAU 1", "LES OISEAUX TRANSMETTENT LE VIRUS"},
     {40, 10, 0, 25, 0, "OISEAU 2", "LES OISEAUX TRANSMETTENT LE VIRUS"},
     {10,  0, 0, 10, 0, "SANG 1", "LE VIRUS SE TRANSMET PAR LE SANG"},
-    {20, 10, 0, 15, 0, "SANG 2", "LE VIRUS SE TRANSMET PAR LE SANG"},
+    {20,  5, 0, 15, 0, "SANG 2", "LE VIRUS SE TRANSMET PAR LE SANG"},
     {40, 15, 0, 25, 0, "SANG 3", "LE VIRUS SE TRANSMET PAR LE SANG"},
 };
 
diff --git a/src/main.c b/src/main.c
index 208cd58..7064f61 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,7 +1,7 @@
 /*
   Project name ......: Plague
-  Version ...........: 1.3.6
-  Last modification .: 7 June 2021
+  Version ...........: 1.3.7
+  Last modification .: 8 June 2021
 
   code and assets provided with licence :
   GNU General Public Licence v3.0
@@ -20,7 +20,7 @@
 #include "mutation_engine.h"
 #include "save.h"
 
-const char *VERSION = "1.3.6";
+const char *VERSION = "1.3.7";
 
 // title_screen : display the title screen
 static void title_screen(void);
diff --git a/src/mutation_engine.c b/src/mutation_engine.c
index 193af6c..de223f9 100644
--- a/src/mutation_engine.c
+++ b/src/mutation_engine.c
@@ -42,7 +42,7 @@ void get_mutation(const struct game *current_game, const int mutation_menu, int
     if (mutation_menu == 3)
     {
         if (current_game->mutations_count[2] < 5) init_mat(8, 4, table, mt_transmissions_1.data);
-        else if (current_game->mutations_count[2] < 10) init_mat(8, 4, table, mt_transmissions_2.data);
+        else if (current_game->mutations_count[2] < 9 ) init_mat(8, 4, table, mt_transmissions_2.data);
         else init_mat(8, 4, table, mt_transmissions_3.data);   
     }
 }
diff --git a/src/mutation_engine.h b/src/mutation_engine.h
index 8a5d8da..8b2ec28 100644
--- a/src/mutation_engine.h
+++ b/src/mutation_engine.h
@@ -5,7 +5,7 @@
 #include "display_engine.h"
 
 // Basic limit research
-#define RESEARCH_LIMIT 250
+#define RESEARCH_LIMIT 300
 
 // mutation_table : contain the map of the mutation available
 struct mutation_table